Based on satellite data, KVERT reported that ash explosions at Karymsky occurred at 0420 on 20 September, producing an ash cloud that drifted 95-100 km NNE. The Aviation Color Code was raised to Orange (the second highest level on a four-color scale).

Karymsky volcano on Russia's Kamchatka Peninsula has a lengthy eruptive history based on both radiocarbon data (back to about 6600 BCE) and historical observations (back to 1771). Much of the volcanic cone is surrounded by lava flows less than 200 years old. The most recent activity, consisting of frequent ash explosions and a few lava flows deposited on the flanks, has been ongoing for several decades. The most recent previous report described numerous ash explosions, persistent thermal anomalies, and moderate seismic activity through 2014 (BGVN 40:09). This report covers similar activity from January 2015 through May 2017. Information was compiled from the Kamchatka Volcanic Eruptions Response Team (KVERT), the Tokyo Volcanic Ash Advisory Center (VAAC), and several sources of satellite data.

Ash-bearing explosions and thermal anomalies characterized activity throughout 2015, beginning with an explosion on 19 January. Ash plumes were common through early March 2016, after which only steam-and-gas emissions and occasional thermal anomalies were noted, although fresh ash deposits were observed near the volcano in the second half of March. A brief episode of explosive activity during 5-8 October 2016 produced low-level ash plumes that drifted for hundreds of kilometers. No additional activity was reported through May 2017.

Activity during 2015. An explosive event at Karymsky on 19 January 2015 signaled a return to activity after a few months of quiet. The ash plume from the explosion extended 50 km SE, and the NASA Earth Observatory captured a satellite image showing trace ash deposits from the event trending SE across the snow-covered landscape (figure 34). Ashfall deposits were seen on 1 March (10-15 km E and SE) and 7 March.

Throughout the year, KVERT reported multiple thermal anomalies and ash plumes each month (table 8). The Tokyo VAAC issued 192 aviation alerts during the year, and the MODVOLC system reported eight thermal alerts in January, one in July, and two in August. Ash plume altitudes ranged from 2.1 to 7 km. Continuous ash emissions were noted during 16 and 29-30 July. The ash plume observed in satellite data on 17 July was 8 km long and 5 km wide. Volcanologists observed multiple explosions during 21-22 July, and helicopter pilots in the area reported explosions on 28 July that then lasted for several days (figure 35). Large plumes were also noted during December; on 22 December one was 8 km long and 6 km wide, and on 25 December one was 56 km long and 6 km wide. The highest altitude plumes were reported at 7 km drifting N on 16 and 20 November 2015 by the Tokyo VAAC. Ash plumes drifted in various directions, and were observed as far as 250 km before dissipating.

Table 8. Summary by month of ash plumes and thermal anomalies reported for Karymsky during 2015. Details include dates of thermal anomalies and ash plumes, maximum plume altitude in kilometers, distance in kilometers of ash plume drift, and direction of drift. Multiple thermal anomalies on a given date are shown in parentheses- 23(4)-after the date. 'Date: 7/8' means time zone boundaries presented different reported days for Kamchatka time (KST) and Universal Time (UTC). Sources are KVERT and Tokyo VAAC for ash plume data; KVERT and MODVOLC for thermal data.

Month

Thermal Anomalies (KVERT)

Thermal Anomalies (MODVOLC)

Ash Plumes

Plume Altitude (km)

Plume Distance (km)

Plume Directions

Jan 2015

11, 18-31

19, 22(2), 23(4), 26

19-23, 27, 31

2.5-5

65-160

ESE, E, N

Feb 2015

6, 21, 24

--

23, 27

2.7

254, 215

ENE

Mar 2015

7, 24-26, 29

--

22, 24-26, 27, 29-30

2.1

154, 150

E, NE, SW

Apr 2015

9, 16-17, 23

--

3, 23, 27

2.7-3.0

85, 35, 140

SE, SE, NE

May 2015

4-6, 15-16, 30

--

16/17, 23

--

27, 45

W, SE

Jun 2015

6, 8-10

--

8-10

4.3

50

SE, E

Jul 2015

6, 13-14, 16, 17, 25, 27-30

13

1, 9, 13, 17, 21-22, 25, 27-30

2-5.1

50-115

SW, S, E, NW, SE

Aug 2015

2, 6, 15, 18-21, 24-25

19, 24

2, 6, 8, 9, 12, 15, 16, 18, 21, 24, 25

4.3-5.8

25-54

N, W, SW, SE

Sep 2015

2, 10, 14-18, 24

--

8, 10, 20

4.3-4.6

10

SE, NE

Oct 2015

4, 8, 11, 20, 22-24, 28

--

3-5, 8, 17-20, 22

2.1-4.6

50, 100

SE, E

Nov 2015

20, 27

--

1/2, 4, 7/8, 10-12, 15-18, 20-21, 30

2.5-7.0

40-160

NE, SE, E, ESE

Dec 2015

3, 6-7, 14, 23-25, 27-28, 31

--

11, 19, 22, 25, 28

3.7-5.5

145

E, NE, NW, W, ENE

Figure 35. Ash plume from an explosion at Karymsky on 30 July 2015. Photo by E. Kalacheva, IVS FEB RAS, courtesy of KVERT.

Activity during January 2016-April 2017. Activity was variable at Karymsky during 2016 (table 9). The Tokyo VAAC issued 132 aviation notices. Ash plumes and thermal anomalies were most frequent during January and February, with over twenty instances of each during February. The plume heights during February exceeded 6 km altitude four times, with the highest plume of the year on 20 February at 7.6 km altitude. Near-continuous ash emissions during the last week of February resulted in satellite observations of ash deposits around the volcano at the end of the month and during the first few days of March (figure 36). Activity decreased significantly during March, although KVERT noted fresh ash deposits again during 18-25 March. Except for thermal anomalies noted on 1 and 6 April, only steam-and-gas emissions were reported; KVERT lowered the Aviation Alert Level from Orange to Yellow (on a four-color scale) at the end of the month. From May to July, KVERT reported a thermal anomaly once each month. Steam-and-gas emissions were the only activity reported in August, and on 2 September, they lowered the Alert Level from Yellow to Green.

Table 9. Summary by month of ash plumes and thermal anomalies reported for Karymsky during 2016. Details include dates of thermal anomalies and ash plumes, maximum plume altitude in kilometers, distance in kilometers of ash plume drift, and direction of drift. Sources are KVERT and Tokyo VAAC for ash plume data; KVERT and MODVOLC for thermal data.

Month

Thermal Anomalies (KVERT)

Thermal Anomalies (MODVOLC)

Ash Plumes

Plume Altitude (km)

Plume Distance (km)

Plume Directions

Jan 2016

1, 3-4, 6-7, 11-15, 18-19, 21, 23, 26, 31

--

3, 5-7, 9, 10, 12-15, 17, 21, 24, 26-28, 31

3.9-7.6

160-270

E, NW, SE

Feb 2016

1-19, 22, 26-29

5

1-21, 26

3.4-7.6

125-270

E, SE, W

Mar 2016

1-4

--

1

5.2

--

NE

Apr 2016

1, 6

--

--

--

--

--

May 2016

26

--

--

--

--

--

Jun 2016

25

--

--

--

--

--

Jul 2016

4

--

--

--

--

--

Aug 2016

--

--

--

--

--

--

Sep 2016

--

--

--

--

--

--

Oct 2016

7, 12, 17

--

5-8

2.4

390

E, SE

Nov 2016

3

--

--

--

--

--

Dec 2016

--

--

--

--

--

--

Figure 36. Steam plume from Karymsky on 21 February 2016, and abundant fresh ashfall around the volcano from recent ash emissions. Photo by E. Nenasheva, courtesy of KVERT.

After six months of quiet, the Tokyo VAAC reported an ash plume on 5 (UTC)/6 (KST) October at 2.4 km altitude extending SE. Aviation alerts were issued through 8 October 2016. Although residing at a fairly low altitude (2.4 km), the plume observed in satellite imagery during 7-8 October was visible in satellite imagery drifting 390 km E and SE before dissipating. KVERT briefly raised the Alert Level to Yellow and then to Orange on 7 and 8 October, and then back to Yellow on 19 October. Three weak thermal anomalies appeared in October and one in November; KVERT lowered the Alert Level to Green on 25 November. Karymsky remained at Alert Level Green through May 2017 with no further reports issued from KVERT or the Tokyo VAAC.

Based on satellite data, KVERT reported that ash explosions at Karymsky occurred at 0420 on 20 September, producing an ash cloud that drifted 95-100 km NNE. The Aviation Color Code was raised to Orange (the second highest level on a four-color scale).

A thermal anomaly over Karymsky was identified in satellite images on 11 August, as well as ash plumes drifting about 400 km SE during 12-13 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

A thermal anomaly over Karymsky was identified in satellite images during 4 and 6-10 August, as well as ash plumes drifting about 70 km NE and SW during 4 and 7-9 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

KVERT reported that satellite images showed a weak thermal anomaly over Karymsky on 1 and 3 August, and ash plumes drifting about 30 km ESE on 3 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

KVERT reported that a weak thermal anomaly over Karymsky was identified in satellite images during 7 and 11-12 July. Ash plumes drifted 170 km SW and SE on 10 and 11 July, respectively. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 23-24 and 27-28 June. An ash plume drifted 55 km SW on 24 June. Explosions on 26 June generated ash plumes that rose to an altitude of 6 km (19,700 ft) a.s.l. and drifted 165 km SE during 26-27 June. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 10-12 and 14-15 June. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 3-8 June. Explosions on 8 June generated ash plumes that rose 2-3 km (6,600-9,800 km) a.s.l. and drifted 70 km E, SE, and SW. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Based on Tokyo VAAC data, KVERT reported that an explosive eruption at Karymsky began at 0040 on 4 June. An ash plume rose 3 km (9,800 ft) a.s.l. and drifted over 40 km NE. The Aviation Color Code was raised to Orange (the second highest level on a four-color scale). Less than four hours later ash plumes rose 2 km (6,600 ft) a.s.l. and drifted 85 km ENE. The VAAC reported that a possible ash plumes rose 4 km 13,000 ft) a.s.l. during 5-6 June and drifted E.

On 19 October KVERT stated that moderate steam-and-gas emissions and an occasional weak thermal anomaly at Karymsky continued to be detected in satellite images. The Aviation Color Code was lowered to Yellow.

Based on satellite image analysis, KVERT reported that during 7-8 October gas, steam, and ash plumes rose from Karymsky and drifted 390 km E and SE. A weak thermal anomaly was detected over the volcano on 7 and 12 October. The Aviation Color Code remained at Orange.

Based on satellite image analysis, KVERT reported that during 5-7 October gas-and-steam plumes containing small amounts of ash rose from Karymsky and drifted 100 km SE. The Aviation Color Code was raised to Yellow. Ash emissions continued to drift SE on 8 October; the total length of the ash plume grew to 388 km. The Aviation Color Code was raised to Orange.

KVERT reported that Karymsky was quiet during March-August, noting that the last moderate explosion occurred in February and the last thermal anomaly over the volcano was detected in May. On 2 September the Aviation Color Code was lowered to Green (the lowest level on a four-color scale).

On 28 April KVERT reported that satellite images over Karymsky showed either cloud cover or quiet conditions at the volcano during March-April. Moderate gas-and-steam emissions continued. The Aviation Color Code was lowered to Yellow.

KVERT reported that moderate activity at Karymsky continued during 1-8 April. Satellite images showed a weak thermal anomaly over the volcano on 1 and 6 April. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 26 February-4 March. Daily satellite images detected a thermal anomaly over the volcano and fresh ash deposits. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 12-19 February. Satellite images detected a daily thermal anomaly, and ash plumes from explosions that drifted about 125 km E. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 5-12 February. Satellite images detected a daily thermal anomaly, and ash plumes that drifted about 170 km E and SE. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 29 January-5 February. Satellite images detected a daily thermal anomaly, and ash plumes that drifted about 270 km E and SE on 31 January and during 1-2 and 4 February. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 22-29 January. Satellite images detected a thermal anomaly on 23 and 26 January, and ash plumes that drifted about 160 km E and NW on 24 and 26 January, respectively. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 15-22 January. Satellite images detected a thermal anomaly during 15, 18-19, and 21 January. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 1-8 January. Satellite images detected a thermal anomaly during 1, 3-4, and 6-7 December, and ash plumes drifting as far as 200 km E during 3 and 5-6 January. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 27 November-4 December. Satellite images detected a thermal anomaly on 27 November and 3 December. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 20-27 November. Satellite images detected a thermal anomaly on 20 November. According to pilot reports, an explosion at 1555 on 30 November generated an ash plume that rose to an altitude of 7.5 km (24,600 ft) a.s.l. and drifted 80 km ESE. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 23-30 October. Satellite images detected a thermal anomaly over the volcano during 23-24 and 28 October. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 16-23 October. Satellite images showed ash plumes drifting 100 km SE during 19-20 and 22 October, and a thermal anomaly over the volcano on 20 and 22 October. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 9-16 October. Satellite images showed a thermal anomaly over the volcano on 11 October. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 2-9 October. Satellite images showed a thermal anomaly over the volcano on 4 and 8 October, and an ash plume that drifted 50 km SE on 8 October. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 18-25 September. Satellite images detected a thermal anomaly on the volcano on 18 and 24 September, and an ash plume that drifted 10 km NE on 20 September. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 11-18 September. Satellite images detected a thermal anomaly on the volcano during 14-18 September. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 4-11 September. Satellite images detected a thermal anomaly on the volcano on 10 September. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 28 August-4 September. Satellite images detected a thermal anomaly on the volcano on 2 September. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 21-28 August. Satellite images detected a thermal anomaly on the volcano during 21 and 24-25 August. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 14-21 August. Satellite images detected ash plumes drifting 54 km SE on 15 August, and a thermal anomaly on the volcano during 15 and 18-20 August. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 7-14 August. Satellite images detected a thermal anomaly on 6 August and ash plumes that drifted 25 km SW on 8 August. The Aviation Color Code remained at Orange.

KVERT reported that moderate explosive activity at Karymsky continued during 31 July-7 August. On 2 and 6 August satellite images detected a thermal anomaly and ash plumes that drifted 40 km N and W. The Aviation Color Code remained at Orange.

KVERT reported that moderate activity at Karymsky likely continued during 17-24 July. Satellite images detected a thermal anomaly on 17 July as well as an ash cloud (8 km long and 5 km wide) that drifted 113 km E. Volcanologists observed multiple explosions during 21-22 July; ash plumes that rose as high as 2 km a.s.l. and drifted SE. The Aviation Color Code remained at Orange.

KVERT reported that explosive activity at Karymsky likely continued during 3-10 July; a thermal anomaly over the volcano was visible in satellite images on 6 July. Weather clouds obscured views of the volcano on the other days. The Aviation Color Code remained at Orange.

KVERT reported that explosive activity at Karymsky likely continued during 3-10 July; a thermal anomaly over the volcano was visible in satellite images on 6 July. Weather clouds obscured views of the volcano on the other days. The Aviation Color Code remained at Orange.

KVERT reported that explosive activity at Karymsky likely continued during 26 June-3 July; a small ash cloud above the volcano was visible in satellite images on 1 July. The Aviation Color Code remained at Orange.

KVERT reported that explosive activity at Karymsky likely continued during 5-12 June. Satellite images detected a thermal anomaly during 6 and 8-10 June, and ash clouds that drifted as far as 50 km SE during 8-9 June. The Aviation Color Code remained at Orange.

KVERT reported that moderate activity at Karymsky likely continued during 15-22 May. Satellite images detected a thermal anomaly during 15-16 May and an ash plume drifting 27 km W on 16 May. The Aviation Color Code remained at Orange.

KVERT reported that during 3-10 April moderate activity at Karymsky continued. Satellite images detected ash plumes drifting 85 km SE on 3 April, and a thermal anomaly over the volcano on 9 April. The Aviation Color Code remained at Orange.

KVERT reported that during 27 March-3 April moderate activity at Karymsky continued. Satellite images detected ash plumes drifting 150 km NE and SW during 27 and 29-30 March, and a thermal anomaly over the volcano on 29 March. The Aviation Color Code remained at Orange.

KVERT reported that during 20-27 March moderate activity at Karymsky continued. Satellite images detected ash plumes drifting 154 km E during 22 and 24-25 March, and a thermal anomaly over the volcano during 24-26 March. The Aviation Color Code remained at Orange.

KVERT reported that during 6-13 March moderate activity at Karymsky continued. Satellite images showed ash deposits extending in different directions and a thermal anomaly on the volcano on 7 March. The Aviation Color Code remained at Orange.

KVERT reported that during 20-27 February moderate seismicity at Karymsky was detected. Satellite images showed a thermal anomaly over the volcano on 21 and 24 February, and ash plumes drifting 254 km ENE on 23 February. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismicity at Karymsky was detected during 13-20 February. Satellite images showed that the volcano was quiet or obscured by clouds. The Aviation Color Code remained at Orange.

KVERT reported that during 6-13 February a moderate explosive eruption at Karymsky continued. Satellite images showed a thermal anomaly over the volcano on 6 February; weather prevented views of the volcano on the other days. The Aviation Color Code remained at Orange.

KVERT reported that during 23-30 January a moderate explosive eruption at Karymsky continued. Satellite images showed a daily thermal anomaly over the volcano, and ash plumes that rose 3.5-4 km above the crater and drifted 160 km E and N during 21-23 and 27 January.

KVERT reported that during 16-23 January a moderate eruption at Karymsky continued. Satellite images showed a thermal anomaly over the volcano during 18-22 January, and ash plumes that drifted 65 km E at an altitude of 5 km (16,400 ft) a.s.l. during 19-22 January.

KVERT reported that a four-minute long explosion from Karymsky was detected by the seismic network beginning at 1115 on 4 October. Pilots observed an ash plume that rose to an altitude of 3 km (10,000 ft) a.s.l. The Aviation Color Code remained at Yellow.

KVERT reported that moderate-to-weak seismic activity continued at Karymsky and maintained Yellow Alert during the week of 12 September. On 10 September satellite data showed an ash plume at that extended about 100 km SE. The volcano was quiet or obscured by clouds on the other days of week.

According to the Tokyo VAAC, ash plumes were detected by satellite images during 10 and 16 September. Plume heights were 2,100-3,000 m (7,000-10,000 ft) a.s.l..

KVERT reported that moderate-to-weak seismic activity continued at Karymsky and maintained Yellow Alert during the week of 5 September. On 3 September satellite data showed an ash plume at 4,000 m (13,100 ft) a.s.l. that extended about 9 km WSW. The volcano was quiet or obscured by clouds on the other days of week.

KVERT reported weak to moderate seismic activity at Karymsky, indicating that Strombolian activity continued during 19-25 July. Satellite views were obscured by clouds or the imagery showed no activity. On 24 July the Aviation Color Code was lowered to Yellow.

KVERT reported weak to moderate seismic activity indicating that Strombolian activity continued at Karymsky during 11-18 July. Satellite views were obscured by clouds or the imagery showed no activity. The Aviation Color Code remained at Orange.

KVERT reported that Strombolian and weak Vulcanian activity continued at Karymsky during 20-26 June. Satellite images detected no activity or were obscured by clouds. The Aviation Color Code remained at Orange.

KVERT reported that Strombolian and weak Vulcanian activity continued at Karymsky during 14-19 June. Satellite images detected a thermal anomaly on 13 and 16 June; clouds obscured the volcano on the other days. The Aviation Color Code remained at Orange.

KVERT reported that Strombolian and weak Vulcanian activity continued at Karymsky during 6-13 June. Satellite images detected a thermal anomaly on 11 June; clouds obscured the volcano on the other days. The Aviation Color Code remained at Orange.

KVERT reported that Strombolian and weak Vulcanian activity continued at Karymsky during 30 May-6 June. Satellite images detected no activity or were obscured by clouds. The Aviation Color Code remained at Orange.

KVERT reported that Strombolian and weak Vulcanian activity continued at Karymsky during 23-30 May. Satellite images detected a thermal anomaly over the volcano on 25 and 27 May. The Aviation Color Code remained at Orange.

KVERT reported that Strombolian and weak Vulcanian activity continued at Karymsky during 9-16 May. Satellite images detected a thermal anomaly on the volcano on 14 May. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity continued at Karymsky during 2-8 May. Satellite images detected a thermal anomaly on the volcano every day except during 3-4 May, days cloud cover obscure views. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity continued at Karymsky during 25 April-2 May. Satellite images detected a thermal anomaly on the volcano on 27 and 30 April and 1 May; cloud cover obscure views on the other days. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity continued at Karymsky during 17-25 April. Satellite images detected a thermal anomaly on the volcano on 19 and 22; cloud cover obscured views on the other days. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity continued at Karymsky during 11-17 April. Satellite images detected a thermal anomaly on the volcano during 15-17; cloud cover obscure views on the other days. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity at Karymsky continued during 28 February-7 March. Satellite images detected a bright thermal anomaly on the volcano daily, and an ash plume that rose to altitudes of 1.5-2 km (3,300-6,600 ft) a.s.l. and drifted 55 km NE on 28 February. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity at Karymsky continued during 21-28 February. Satellite images detected a daily thermal anomaly on the volcano, and an ash plume that rose to an altitude of 1.5-2 km (3,300-6,600 ft) a.s.l. and drifted 55 km NE. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity at Karymsky continued during 14-21 February. Satellite images detected a daily thermal anomaly on the volcano. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity at Karymsky continued during 7-14 February. Satellite images detected a thermal anomaly on the volcano on 12 February; cloud cover obscured views of the volcano on the other days. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity at Karymsky continued during 24-31 January. Satellite images detected a daily bright thermal anomaly on the volcano. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity at Karymsky continued during 17-24 January. Satellite images detected a bright thermal anomaly on the volcano daily, and ash plumes that drifted 110 km E. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity at Karymsky continued during 10-17 January. Satellite images detected a bright thermal anomaly on the volcano daily. On 19 January satellite images showed an ash plume that rose to altitudes of 3-3.5 km (8,200-9,800 ft) a.s.l. and drifted 40 km SSE. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity at Karymsky continued during 3-10 January. Satellite images detected a bright thermal anomaly on the volcano daily, and an ash plume that drifted 10 km SSE on 8 January. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity at Karymsky continued during 27 December 2013-2 January 2014. Satellite images detected a bright thermal anomaly on the volcano daily, and an ash plume that rose as high as 2 km and drifted 120 km SE on 1 January. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity at Karymsky continued during 20-27 December. Satellite images detected a bright thermal anomaly on the volcano daily. The Aviation Color Code remained at Orange.

KVERT reported that Vulcanian and Strombolian activity at Karymsky continued during 13-20 December. Satellite images detected a bright thermal anomaly on the volcano daily, and gas-and-steam plumes that drifted 30 km SW on 18 December. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity at Karymsky was detected during 6-13 December, and Vulcanian and Strombolian activity continued. Satellite images detected a bright thermal anomaly on the volcano daily, and ash plumes that drifted 150 km E and SE during 6-7 and 10 December. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity at Karymsky was detected during 24-31 October. During this time period, satellite images also detected a daily bright thermal anomaly on the volcano. Ash plumes drifted 65 km SE and W during 24-26 and 29-30 October. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity at Karymsky was detected during 11-18 October. Satellite images showed a thermal anomaly on the volcano on 11 and 16 October, and an ash plume drifting 18 km SE on 12 October. The thermal anomalies and short ash plume possibly indicated Strombolian and weak Vulcanian activity. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity at Karymsky was detected during 23-30 August. Based on seismic interpretation, possible ash plumes rose to an altitude of 3.5 km (11,500 ft) a.s.l. Satellite imagery showed a weak thermal anomaly on the volcano during 26-27 August. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity at Karymsky was detected during 16-23 August. Based on seismic interpretation by Kamchatka Branch of Geophysical Services (KBGS; Russian Academy of Sciences), possible ash plumes rose to an altitude of 4 km (13,100 ft) a.s.l. on 19 August and to an altitude of 2 km (6,600 ft) a.s.l. the other days of the week. Satellite imagery showed a weak thermal anomaly on the volcano on 17, 20, and 22 August. On 22 August a pilot observed an ash plume near the volcano; that same day an ash plume was visible in satellite images drifting 30 km ESE at altitudes of 1-1.5 km (3,300-4,900 ft) a.s.l. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity at Karymsky was detected during 9-17 August. Based on seismic interpretation, possible ash plumes rose to an altitude of 6 km (19,700 ft) a.s.l. on 15 August and to an altitude of 4 km (13,100 ft) a.s.l. the other days of the week. Satellite imagery showed a weak thermal anomaly on the volcano on 15 August; cloud cover prevented observations on the other days. The Aviation Color Code remained at Orange.

KVERT reported that technical problems prevented seismic data collection at Karymsky during 26 July-2 August. A thermal anomaly over the volcano was detected in satellite images during 29-31 July and 1 August; weather conditions prevented views on the other days.

On 6 August at 1035 a plume was observed by helicopter pilots (and confirmed by volcanologists at Tolbachik) rising 6 km (19,700 ft) a.s.l. and drifting 30 km E. An explosion at 1145 generated an ash cloud observed in satellite images that rose to an altitude of 4 km (13,100 ft) and drifted 45 km ESE. The ash cloud was 9 x 14 km. Ash plumes that were observed in satellite images at 1332 and 1512 rose to altitudes of 4.2 km (13,800 ft) and drifted 30 km ESE, and 4 km (13,100 ft) and drifted 80 km ESE, respectively. The Aviation Color Code remained at Orange.

KVERT reported that technical problems prevented seismic data collection at Karymsky during 14-21 June. A thermal anomaly over the volcano was detected in satellite images during 17-18 June; weather conditions prevented views on the other days. The Aviation Color Code remained at Orange.

KVERT reported that technical problems prevented seismic data collection at Karymsky during 7-14 June. A thermal anomaly over the volcano was detected in satellite images during 8 and 12-13 June. The Aviation Color Code remained at Orange.

KVERT reported that weak seismic activity was detected at Karymsky during 25-26 May; technical problems prevented seismic data collection on the other days during 24-31 May. Satellite data showed a thermal anomaly on the volcano on 25 and 28 May, during periods of clearer weather conditions. The Aviation Color Code remained at Orange.

KVERT reported that satellite data showed a thermal anomaly on Karymsky on 26 April. Two streaks of ash deposits near the volcano were observed during 1-2 May: about 15 km to the W and about 30 km to the NW of the volcano. Technical problems prevented seismic data collection during 26 April-3 May. The Aviation Color Code remained at Orange.

KVERT reported that weak-to-moderate seismic activity at Karymsky was detected during 15-22 March. Satellite data showed a weak thermal anomaly on the volcano on 18 March. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity at Karymsky was detected during 22 February-1 March. Satellite imagery showed a thermal anomaly on the volcano during 21 and 25-28 February. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity at Karymsky was detected during 15-22 February. Possible ash explosions during 14, 16, and 19-20 February produced ash plumes that rose 4 km (13,100 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano during 14 and 18-20 February. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity at Karymsky was detected during 8-15 February. Possible ash explosions on 11 February produced an ash plume that rose 3.2 km (10,500 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano during 12-13 February. The Aviation Color Code remained at Orange.

KVERT reported that weak seismic activity at Karymsky was detected during 1-8 February. Satellite imagery showed a thermal anomaly on the volcano on 31 January and 1 February. The Aviation Color Code remained at Orange.

KVERT reported that weak seismic activity at Karymsky was detected during 25 January-1 February. Satellite imagery showed a thermal anomaly on the volcano during 24-25 and 30 January. The Aviation Color Code remained at Orange.

Based on information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 30 January an ash plume rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted SE. An ash plume was not detected in satellite imagery.

KVERT reported that weak-to-moderate seismic activity at Karymsky was detected during 18-25 January, indicating that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano during 20-23 January; cloud cover prevented observations on the other days. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity at Karymsky was detected during 11-18 January, indicating that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano on 11 and 14 January; cloud cover prevented observations on the other days. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity at Karymsky was detected during 28 December-4 January. Satellite imagery showed a thermal anomaly on the volcano on 28 and 30 December, as well as on 1 January. The Aviation Color Code remained at Orange.

KVERT reported that weak-to-moderate seismic activity at Karymsky was detected during 21-28 December. Satellite imagery showed a thermal anomaly on the volcano during 26-27 December. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity at Karymsky was detected during 23-30 November. Satellite imagery showed a thermal anomaly on the volcano on 23 and 28 November; cloud cover obscured views on the other days. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity at Karymsky was detected during 16-23 November. Satellite imagery showed a big thermal anomaly on 20 and 22 November; cloud cover obscured views on the other days. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity continued at Karymsky during 2-9 November. Satellite imagery detected a thermal anomaly on the volcano during 7-8 November. The Aviation Color Code remained at Orange. Based on analyses of satellite imagery, the Tokyo VAAC reported that on 10 November a possible eruption produced a plume that rose to an altitude of 5.5 km (18,000 ft) a.s.l. and drifted E.

Based on analyses of satellite imagery, the Tokyo VAAC reported that on 16 October a possible eruption produced a plume that rose to an altitude of 4 km (13,000 ft) a.s.l. and drifted N. Ash was detected in a subsequent image.

KVERT reported moderate seismic activity from Karymsky during 28 September-5 October. Seismic data indicated that possible ash plumes rose to an altitude of 4 km (13,100 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano on 28 September and 2 October. The Aviation Color Code remained at Orange.

Based on and information from the Kamchatka Branch of the Geophysical Service (KGBS), the Tokyo VAAC reported that on 6 October ash plumes rose to altitudes of 6.1-6.7 km (20,000-22,000 ft) a.s.l. and drifted SE. The plume altitudes were based on seismic data analyses.

KVERT reported moderate seismic activity from Karymsky during 17-27 August, and indicated that possible ash plumes rose to an altitude of 5.8 km (19,000 ft) a.s.l. on 25 August and to an altitude of 2.4 km (7,900 ft) a.s.l. on 27 August. Satellite imagery showed a daily thermal anomaly on the volcano. The Aviation Color Code remained at Orange.

Based on information from KEMSD, the Tokyo VAAC reported that on 25 August an eruption produced a plume that rose to an altitude of 5.8 km (19,000 ft) a.s.l. The altitude was based on seismic analysis.

KVERT reported moderate seismic activity from Karymsky during 3-10 August. Satellite imagery showed a weak thermal anomaly on the volcano. A possible gas-and-ash explosion on 8 August may have produced a plume that rose to an altitude of 3.3 km (10,800 ft) a.s.l. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity from Karymsky continued to be detected during 6-16 July, and indicated that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. Satellite imagery showed a weak thermal anomaly on the volcano on 12 and 14 July. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity from Karymsky continued to be detected during 29 June-10 July, and indicated that possible ash plumes rose to altitudes of 2.1-3.3 km (6,900-10,800 ft) a.s.l. during 29 June-7 July. Satellite imagery showed a weak thermal anomaly on the volcano on 29 June and 1 July. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity from Karymsky continued to be detected during 22-29 June, and indicated that possible ash plumes rose to an altitude of 3.6 km (11,800 ft) a.s.l. Satellite imagery showed a weak thermal anomaly on the volcano on 22 June. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity from Karymsky continued to be detected during 15-22 June, and indicated that possible ash plumes rose to an altitude of 3.6 km (11,800 ft) a.s.l. during 16-19 June. Satellite imagery showed a weak thermal anomaly on the volcano during 20-21 June. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity from Karymsky continued to be detected during 8-15 June, and indicated that possible ash plumes rose to an altitude of 3 km (9,800 ft) a.s.l. during 8-13 June. Meteorological cloud cover prevented satellite image views. Based on analysis of seismic data, KVERT reported that on 18 June possible ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity from Karymsky continued to be detected during 31 May-8 June, and indicated that possible ash plumes rose to an altitude of 2.4 km (8,000 ft) a.s.l. on 31 May. Satellite imagery showed a thermal anomaly on the volcano during 3-4 and 6 June. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity from Karymsky continued to be detected during 25 May-1 June. Satellite imagery showed a thermal anomaly on the volcano during 25, 28, and 30-31 May. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity from Karymsky continued to be detected during 18-25 May, and indicated that possible ash plumes rose to an altitude of 2.2 km (7,200 ft) a.s.l. on 17 and 19 May. Satellite imagery showed a thermal anomaly on the volcano during 17-18, 20, 22, and 24 May. The Aviation Color Code remained at Orange.

Based on information from the Yelizovo Airport (UHPP) and analyses of satellite imagery, the Tokyo VAAC reported that on 27 May an ash plume drifted NE at an altitude of 3 km (10,000 ft) a.s.l.

KVERT reported that moderate seismic activity from Karymsky continued to be detected during 11-18 May, and indicated that possible ash plumes rose to an altitude of 1.8 km (6,000 ft) a.s.l. on 10 and 14 May. Satellite imagery showed a thermal anomaly on the volcano during 10-13 and 16 May. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity from Karymsky continued to be detected during 4-11 May, and indicated that possible ash plumes rose to an altitude of 2 km (6,600 ft) a.s.l. during 7-8 May. Satellite imagery showed a daily thermal anomaly on the volcano. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity from Karymsky continued to be detected during 27 April-4 May, and indicated that possible ash plumes rose to an altitude of 2.3 km (7,600 ft) a.s.l. during 26-27 April and 2 May. Satellite imagery showed a gas-and-steam plume drifting 65 km SE on 27 April; a thermal anomaly was present during 27, 29, and 30 April and 2-3 May. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity from Karymsky continued to be detected during 20-27 April, and indicated that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. during 20 and 24-25 April. Satellite imagery showed a daily thermal anomaly on the volcano. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity from Karymsky continued to be detected during 13-20 April. Satellite imagery showed a thermal anomaly on the volcano during 15-19 April. The Aviation Color Code remained at Orange.

KVERT reported that during 7-13 April moderate seismic activity from Karymsky continued to be detected, and indicated that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano during 7 and 9-10 April, and ash deposits 15 km long on the E flank on 11 April. The Aviation Color Code remained at Orange.

KVERT reported that during 30 March-6 April moderate seismic activity from Karymsky continued to be detected, and indicated that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano on 29 March. The Aviation Color Code remained at Orange.

KVERT reported that during 23-30 March seismic activity from Karymsky continued to be detected, and indicated that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. during 22-26 March. Satellite imagery showed a thermal anomaly on the volcano almost daily. The Aviation Color Code remained at Orange.

KVERT reported that during 16-23 March seismic activity from Karymsky continued to be detected, and indicated that possible ash plumes rose to an altitude of 3 km (9,800 ft) a.s.l. during 17 and 20-21 March. Satellite imagery showed a thermal anomaly on the volcano on 15 and 17 March; cloud cover prevented observations on the other days. The Aviation Color Code remained at Orange.

KVERT reported that during 9-16 March seismic activity from Karymsky continued to be detected and indicated that possible ash plumes rose to an altitude of 3.1 km (10,100 ft) a.s.l. on 14 March. Satellite imagery showed a thermal anomaly on the volcano during 10-13 March. The Aviation Color Code remained at Orange.

KVERT reported that during 2-9 March seismic activity from Karymsky continued to be detected and indicated that possible ash plumes rose to an altitude of 3.4 km (11,000 ft) a.s.l. on 3 March. Satellite imagery showed a thermal anomaly on the volcano on 2 March. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 24 February-2 March, and indicated that possible ash plumes rose to an altitude of 3.9 km (12,800 ft) a.s.l. during 23-27 February. Satellite imagery showed a thermal anomaly on the volcano on 25 February; clouds obscured views on the other days. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 17-24 February, and indicated that possible ash plumes rose to an altitude of 3.5 km (11,500 ft) a.s.l. Satellite imagery showed a thermal anomaly at the volcano during 16-21 February and an ash plume that drifted 15 km E on 21 February. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 10-17 February and indicated that possible ash plumes rose to an altitude of 4.6 km (15,000 ft) a.s.l. Satellite imagery showed a thermal anomaly at the volcano all week. According to visual observations from Koryaksky volcano, gas-and-steam activity occurred at Karymsky on 12 February. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 3-10 February and indicated that ash plumes possibly rose to an altitude of 4.1 km (13,500 ft) a.s.l. Satellite imagery showed a thermal anomaly at the volcano all week and an ash cloud 3 km long by 7 km wide that drifted 10 km SE on 6 February. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 27 January-3 February and indicated that ash plumes possibly rose to an altitude of 2.6 km (8,530 ft) a.s.l. during 28 and 30-31 January. Satellite imagery showed a thermal anomaly at the volcano all week and gas-and-steam plumes containing ash that were drifting as far as 80 km E during 30-31 January and on 1 February. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 19-27 January and indicated that ash plumes possibly rose to an altitude of 3 km (9,840 ft) a.s.l. during 19-21 and on 25 January. Satellite imagery showed a thermal anomaly at the volcano during 21-24 January and gas-and-steam plumes containing ash that were drifting as far as 70 km NW on 23 January. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 13-20 January and that seismicity indicated the possibility of ash plumes to an altitude of 3.3 km (10,800 ft) a.s.l. Satellite imagery showed a thermal anomaly at the volcano during 14-15 January; clouds prevented views on the other days. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 6-13 January and indicated that possible ash plumes rose to an altitude of 4.2 km (13,800 ft) a.s.l. Satellite imagery showed a thermal anomaly at the volcano during 5-11 January and weak ash plumes that drifted 40 km E and NE on 6, 7, and 11 January. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 30 December-6 January and indicated that possible ash plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano all week. An ash cloud 10 km long and 2 km wide drifted 56 km SSE on 1 January. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 23-30 December and indicated that possible ash plumes rose to an altitude of 5 km (16,400 ft) a.s.l. Satellite imagery showed a thermal anomaly at the volcano during 22-24 and 27-28 December; clouds prevented views on the other days. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 16-23 December and indicated that possible ash plumes rose to an altitude of 4.1 km (13,500 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano on 21 December and a gas-and-steam plume with possible ash that drifted 40 km S on 20 December. The Aviation Color Code remained at Orange.

Based on information from KEMSD and satellite imagery, the Tokyo VAAC reported that on 26 December an eruption produced a plume that rose to an altitude of 5.2 km (17,000 ft) a.s.l. The altitude was based on seismic analysis.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 9-16 December and indicated that possible ash plumes rose to an altitude of 4.1 km (13,500 ft) a.s.l. during 8-10 and 14 December. Satellite imagery showed a daily thermal anomaly and ash plumes that drifted 160 km SE during 12-13 December. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 2-9 December and indicated that possible ash plumes rose to an altitude of 3.6 km (11,800 ft) a.s.l. Satellite imagery showed a daily thermal anomaly and ash plumes that drifted 90 km E on 3, 7, and 8 December. The Aviation Color Code remained at Orange. Based on information from KVERT, the Tokyo VAAC reported that on 13 December an ash plume rose to an altitude of 3.0 km (10,000 ft) a.s.l. and drifted E.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 25 November-2 December and indicated that possible ash plumes rose to an altitude of 3.8 km (12,500 ft) a.s.l. during the week. Satellite imagery showed a thermal anomaly on the volcano during 28-30 November and 1 December. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 18-25 November and indicated that possible ash plumes rose to an altitude of 2.8 km (9,200 ft) a.s.l. during 19-22 November. Satellite imagery showed a thermal anomaly on the volcano during 18, 20, and 24 November. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 11-18 November, and indicated that possible ash plumes rose to an altitude of 3.9 km (12,800 ft) a.s.l. Satellite imagery showed ash plumes that drifted 172 km E on 11 November and a thermal anomaly on the volcano during 11-12 November. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 4-11 November, and indicated that possible ash plumes rose to an altitude of 3.5 km (11,500 ft) a.s.l. Satellite imagery showed either no activity, possibly due to cloud cover. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 28 October-4 November, and indicated that possible ash plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. during 27-30 October and 1-2 November. Satellite imagery showed ash plumes drifting 130 km SE during 29-30 October and a thermal anomaly on the volcano during 29-31 October. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 21-28 October, and indicated that possible ash plumes rose to an altitude of 3.7 km (12,100 ft) a.s.l. during 20 and 23-24 October. Satellite imagery showed a daily thermal anomaly on the volcano and an ash plume that rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted 15 km NE on 26 October. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 14-21 October, and indicated that possible ash plumes rose to an altitude of 3.3 km (10,800 ft) a.s.l. during 13-15 October and to lesser altitudes the other days of the week. Satellite imagery showed a thermal anomaly on the volcano on 14 and 16 October. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 7-14 October and indicated that possible ash plumes rose to an altitude of 2.2 km (7,200 ft) a.s.l. Ash plumes possibly rose to an altitude of 3.8 km (12,500 ft) a.s.l. on 7 October. Satellite imagery showed a thermal anomaly on the volcano on 6 and 8 October. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 30 September-7 October and indicated that possible ash plumes rose to an altitude of 3.2 km (10,500 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano during 4-5 October. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 23-30 September and indicated that possible ash plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano on 24 September and ash plumes that drifted 80 km SE during 28-29 September. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 16-23 September and indicated that possible ash plumes rose to altitudes of 5-6 km (16,400-19,700 ft) a.s.l. during 16-17 September. A thermal anomaly was detected in satellite imagery during 16, 18, and 20 September. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity continued at a moderate level at Karymsky during 9-15 September, and indicated that possible ash plumes rose to an altitude of 4.6 km (15,100 ft) a.s.l. during 13-14 September. An observer in the area noted that ash explosions produced ash plumes all week that did not rise higher than 3.5 km (11,500 ft) a.s.l. A thermal anomaly was detected daily in satellite imagery and ash plumes drifted 80 km E and SE during 11-12 and 14 September. The Aviation Color Code remained at Orange.

Based on information from Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 20 September an ash plume rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted NE.

KVERT reported that during 2-9 September moderate seismic activity continued at Karymsky, indicating that possible ash plumes rose to an altitude of 3.5 km (11,500 ft) a.s.l. A thermal anomaly on the volcano was detected daily in satellite imagery. The Aviation Color Code remained at Orange.

KVERT reported that during 26 August-1 September moderate seismic activity continued at Karymsky, indicating that possible ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. Gas-and-steam plumes containing ash drifted 40 km E on 26 and 29 August. A thermal anomaly on the volcano was detected by satellite during 26 and 29-30 August. The Aviation Color Code remained at Orange.

Based on information from Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 2 September an ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted NE. Ash plumes rose to an altitude of 2.1 km (7,000 ft) a.s.l. during 5-6 September and drifted SE and SW.

KVERT reported that during 19-26 August moderate seismic activity continued at Karymsky, indicating that possible ash plumes rose to an altitude of 5.2 km (17,000 ft) a.s.l. A thermal anomaly on the volcano was detected by satellite during 21-25 August. Gas-and-steam plumes containing ash drifted 18 and 65 km E on 18 and 24 August, respectively. The Aviation Color Code remained at Orange.

Based on information from Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 29 August an ash plume rose to an altitude of 7.3 km (24,000 ft) a.s.l. and drifted E.

KVERT reported that during 12-19 August moderate seismic activity continued at Karymsky, indicating that possible ash plumes rose to an altitude of 4.2 km (13,800 ft) a.s.l. A thermal anomaly on the volcano was detected by satellite during 14 and 17-18 August; cloud cover prevented observations on the other days. The Aviation Color Code remained at Orange.

KVERT reported that during 5-12 August moderate seismic activity continued at Karymsky and possible ash plumes rose to an altitude of 3 km (9,800 ft) a.s.l. A thermal anomaly on the volcano was detected daily by satellite. During 7-8 August, pilots observed ash plumes that rose to an altitude of 4 km (13,100 ft) a.s.l. and drifted E. Satellite imagery also showed an ash cloud, 3 by 1.5 km in dimension, that was 10 km W of the volcano on 10 August. The Aviation Color Code remained at Orange.

KVERT reported that during 29 July-5 August moderate seismic activity continued at Karymsky and possible ash plumes rose to an altitude of 5.5 km (18,000 ft) a.s.l. A thermal anomaly on the volcano was detected by satellite during 30 July-3 August; cloud cover prevented observations on the other days. The Aviation Color Code remained at Orange.

Based on information from Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 8 August an ash plume rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted E.

KVERT reported that during 22-29 July moderate seismic activity continued at Karymsky and possible ash plumes rose from the crater. A thermal anomaly on the volcano was detected by satellite during 22 and 24-27 July; cloud cover prevented observations on the other days. The Aviation Color Code remained at Orange.

Based on information from Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 30 July an ash plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted SW.

KVERT reported that during 15-22 July moderate seismic activity continued at Karymsky and possible ash plumes rose to an altitude of 4 km (13,000 ft) a.s.l. A thermal anomaly on the volcano was detected by satellite during 14, 16, and 18-21 July. The Aviation Color Code remained at Orange.

KVERT reported that during 8-15 July moderate seismic activity continued at Karymsky and possible ash plumes rose to an altitude of 4 km (13,000 ft) a.s.l. A thermal anomaly on the volcano was detected by satellite on 8, 11, and 14 July. An ash plume observed by pilots on 12 July drifted 20 km SW. The Aviation Color Code remained at Orange.

KVERT reported that during 1-8 July moderate seismic activity continued at Karymsky and possible ash plumes rose to an altitude of 4 km (13,100 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano during 2 and 4-5 June, and ash plumes that drifted 14 km NW and 38 km N on 2 and 5 July, respectively. The Aviation Color Code remained at Orange.

Based on information from Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 12 July an ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted SW.

KVERT reported moderate seismic activity at Karymsky during 17-24 June and that possible ash plumes rose to an altitude of 3.9 km (12,800 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano during 16-17 June. The Aviation Color Code remained at Orange.

KVERT reported moderate seismic activity at Karymsky during 10-16 June and that possible ash plumes rose to an altitude of 5.5 km (18,000 ft) a.s.l. Satellite imagery showed a weak thermal anomaly on the volcano during 10-14 June and an ash plume that drifted 90 km NE on 14 June. The Aviation Color Code remained at Orange.

KVERT reported moderate seismic activity at Karymsky during 3-10 June and that possible ash plumes rose to an altitude of 6 km (15,100 ft) a.s.l. Satellite imagery showed a thermal anomaly during 3-4 June and an ash plume that drifted 254 km SE on 4 June. The Aviation Color Code remained at Orange.

KVERT reported moderate seismic activity at Karymsky during 20-27 May. Possible ash plumes rose to an altitude of 6.5 km (21,300 ft) a.s.l. on 21 May and to an altitude of 3.5 km (11,500 ft) a.s.l. on the other days. Satellite imagery showed a thermal anomaly during 19-20, 22, and 24 May, and ash plumes that drifted 38 km SW on 22 May. The Aviation Color Code remained at Orange.

KVERT reported moderate seismic activity at Karymsky during 13-20 May. Seismic data indicated that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. A thermal anomaly was detected in satellite imagery during 16-17 and 19 May. The Aviation Color Code remained at Orange. Based on information from KVERT, the Tokyo VAAC reported that on 21 May an eruption produced a plume that rose to an altitude of 6.7 km (22,000 ft) a.s.l.

KVERT reported moderate seismic activity at Karymsky during 6-13 May. Possible ash plumes rose to an altitude of 6 km (19,700 ft) a.s.l. on 10 May and to an altitude of 4.2 km (13,800 ft) a.s.l. on the other days. Pilots reported that on 6 May ash plumes rose to an altitude of 3 km (9,800 ft) a.s.l. Satellite imagery showed a thermal anomaly and ash plumes that drifted 340 km E during 6-7 May. The Aviation Color Code remained at Orange.

KVERT reported moderate seismic activity at Karymsky during 29 April-6 May. Seismic data indicated that possible ash plumes rose to an altitude of 4.9 km (16,000 ft) a.s.l. A thermal anomaly was detected in satellite imagery during 1-4 May. The Aviation Color Code remained at Orange. Based on analyses of satellite imagery and information from KVERT, the Tokyo VAAC reported that on 7 May ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted SE.

KVERT reported moderate seismic activity at Karymsky during 1-7 April. Seismic data indicated that possible ash plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. A thermal anomaly was detected in satellite imagery on 2 and 4 April and ash-and-gas plumes drifted in multiple directions as far as 48 km during 1-2 and 4 April. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity was detected at Karymsky during 10-18 March. Seismic data during 10-16 March indicated that possible ash plumes rose to an altitude of 5.8 km (19,700 ft) a.s.l. A thermal anomaly was detected in satellite imagery during 11-14 and 16 March. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity was detected at Karymsky during 4-11 March. Seismic data during 3-5 March indicated that possible ash plumes rose to an altitude of 4 km (13,100 ft) a.s.l. A thermal anomaly was detected in satellite imagery during 7-9 March. The Aviation Color Code remained at Orange. Based on information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported that an ash plume rose to an altitude of 7.3 km (24,000 ft) a.s.l. and drifted N on 13 March.

KVERT reported that moderate seismic activity was detected at Karymsky during 25 February-4 March. Seismic data indicated that possible ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. Satellite imagery showed a thermal anomaly over the volcano on 25 February and 2 March. The Aviation Color Code remained at Orange.

KVERT reported that moderate seismic activity was detected at Karymsky during 14-21 January. Seismic data showed that possible ash plumes rose to an altitude of 4.6 km (15,100 ft) a.s.l. A thermal anomaly was observed in satellite imagery during 15 and 18-20 January, and an ash plume drifted 24 km SW on 20 January. Based on analyses of satellite imagery, the Tokyo VAAC reported that eruptions during 24-25 January produced plumes that rose to altitudes of 3.4-4.6 km (11,000-15,000 ft) a.s.l. and drifted SE. The Aviation Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels on 1 and 5 January, suggesting that possible ash plumes rose to an altitude of 3.8 km (12,500 ft) a.s.l. Seismic activity did not exceed background levels on the other days during 31 December-7 January. A thermal anomaly was detected daily in satellite imagery. An ash plume drifting 140 km SE was also seen in imagery on 2 January. Based on a pilot observation, the Tokyo VAAC reported that on 5 January an ash plume rose to an altitude of 4.6 km (15,000 ft) a.s.l.

KVERT reported that seismic activity at Karymsky was above background levels during 23-26 December and did not exceed background levels during 27-30 December. Seismic data suggested that possible ash plumes rose to an altitude of 4.3 km (14,100 ft) a.s.l. Thermal anomalies were detected in satellite imagery during 23-24 December; cloud cover prevented views on the other days. The Aviation Color Code level remained at Orange.

Based on a Yelizovo Airport (UHPP) notification, the Tokyo VAAC reported that on 31 December an ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted E.

KVERT reported that seismic activity at Karymsky was slightly above background levels during 16-19 December and did not exceed background levels during 20-24 December. Seismic data suggested that possible ash plumes rose to an altitude of 3 km (9,800 ft) a.s.l. Thermal anomalies were detected in satellite imagery during 18-21 December. The Aviation Color Code level remained at Orange.

KVERT reported that seismic activity from Karymsky was above background levels during 11-19 November, suggesting that possible ash plumes rose to an altitude of 5.2 km (17,100 ft) a.s.l. on 13 and 17 November. Satellite imagery showed a thermal anomaly over the volcano during 11-18 November. Ash clouds with dimensions as large as 23 x 10 km were detected in imagery 82 km NE on 16 November and 15 km NE on 17 November. The Aviation Color Code level remained at Orange.

KVERT reported that seismic activity from Karymsky was above background levels during 9-10 November, suggesting that possible ash plumes rose to altitudes of 3.5-4.9 km (11,500-16,100 ft) a.s.l. Seismic activity was at background levels on the other days during 5-12 November. Satellite imagery showed a daily thermal anomaly over the volcano. The Aviation Color Code level remained at Orange.

KVERT reported that seismic activity from Karymsky was above background levels during 21-23 October and at background levels during 24-29 October. Satellite imagery showed a thermal anomaly over the volcano during 22-25 October and an ash plume that drifted 40 km E on 23 October. The Aviation Color Code level remained at Orange.

KVERT reported that seismic activity from Karymsky was above background levels during 15-22 October, suggesting that possible ash plumes rose to altitudes of 2-4 km (6,600-13,100 ft) a.s.l. Volcanologists working at Karymsky observed Strombolian activity at night, along with ash plumes during 14-16 October that rose to altitudes of 2.5-3 km (8,200-10,000 ft) a.s.l. and drifted E. A thermal anomaly was seen in satellite imagery during 15-16 and 18-19 October. The Aviation Color Code level remained at Orange.

KVERT reported that seismic activity from Karymsky was above background levels during 8-15 October, suggesting that possible ash plumes rose to altitudes of 2-3 km (6,600-9,800 ft) a.s.l. Volcanologists working at Karymsky observed Strombolian activity at night, along with ash plumes during 7-10 October that rose to an altitude of 2.5 km (11,500 ft) a.s.l. and drifted E. Satellite imagery showed ash plumes that drifted 35 km SE on 7 and 8 October and thermal anomalies on the volcano during 7-10, 12, and 14 October. Based on information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 16 October an ash plume rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted SE. The Aviation Color Code level remained at Orange.

KVERT reported that seismic activity from Karymsky was at background levels during 22-24 September and above background levels during 25-29 September. The elevated seismicity suggested that ash explosions had occurred. Ash plumes rose to altitudes of 3-4.5 km (9,800-14,800 ft) a.s.l. during 25-27 September. Thermal anomalies were seen in satellite imagery on 23, 25, and 28 September, and ash plumes drifted 83 km SE on 28 September. The Aviation Color Code level remained at Orange.

KVERT reported that during 10-17 September seismic activity from Karymsky was above background levels, and suggested that possible ash plumes rose to an altitude of 3.2 km (10,500 ft) a.s.l. on 15 September. Satellite imagery showed a thermal anomaly over the volcano during 10-11 and 14 September. The Aviation Color Code level remained at Orange.

KVERT reported that during 3-10 September seismic activity from Karymsky was above background levels and suggested that possible ash plumes rose to an altitude of 3.2 km (10,500 ft) a.s.l. Satellite imagery showed a thermal anomaly over the volcano during the week. The Aviation Color Code level remained at Orange.

KVERT reported that during 27 August-3 September seismic activity from Karymsky was above background levels and suggested that possible ash plumes rose to an altitude of 3.7 km (12,100 ft) a.s.l. Satellite imagery showed a thermal anomaly over the volcano during the week and an ash plume that drifted 23 km on 28 August. The Aviation Color Code level remained at Orange.

KVERT reported that during 20-27 August seismic activity from Karymsky was above background levels and suggested that possible ash plumes rose to an altitude of 3.8 km (12,500 ft) a.s.l. Satellite imagery showed a thermal anomaly over the volcano during 20 and 23-24 August. The Aviation Color Code level remained at Orange.

KVERT reported that during 13-20 August seismic activity from Karymsky was above background levels and suggested that possible ash plumes rose to an altitude of 3 km (9,800 ft) a.s.l. Satellite imagery showed a thermal anomaly over the volcano during 14-15 August and ash plumes that drifted 100 km E. The Aviation Color Code level remained at Orange.

KVERT reported that during 6-13 August seismic activity from Karymsky was above background levels and suggested that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. A thermal anomaly over the volcano was detected in satellite imagery during 7-8 and 10-11 August. Based on analyses of satellite imagery and information from KVERT, the Tokyo VAAC reported an eruption on 16 August. A subsequent notice stated that ash had dissipated. The Aviation Color Code level remained at Orange.

KVERT reported that during 30 July-6 August seismic activity from Karymsky was above background levels and suggested that possible ash plumes rose to an altitude of 2 km (6,700 ft) a.s.l. A thermal anomaly over the volcano was detected in satellite imagery during 29-30 July and 1-2 and 4 August. Imagery also showed ash plumes that drifted 17 km NE on 2 and 3 August. The Aviation Color Code level remained at Orange.

KVERT reported that during 23-24 and 28 July seismic activity from Karymsky was above background levels and suggested that possible ash plumes rose to an altitude of 2 km (6,700 ft) a.s.l. Seismic data were not available other days during 25-30 July due to technical problems. A daily thermal anomaly was detected in satellite imagery. Imagery also showed ash plumes that drifted 15 km SE on 26 July. The Aviation Color Code level remained at Orange.

KVERT reported that during 16-23 July seismic activity from Karymsky was above background levels and suggested that possible ash plumes rose to an altitude of 3 km (9,800 ft) a.s.l. A daily thermal anomaly was detected in satellite imagery. Imagery also showed ash plumes that drifted 58 km SW on 19 July and 85 km SE on 21 July. The Aviation Color Code level remained at Orange.

KVERT reported that satellite imagery showed ash plumes from Karymsky drifting 30 km W and S on 7 and 8 July and a thermal anomaly over the volcano during 8-10 and 12 July. Seismic activity was above background levels during 12-14 July and suggested that possible ash plumes rose to an altitude of 3.3 km (10,800 ft) a.s.l. Seismic data were not available other days during 9-16 July due to technical problems. Based on analyses of satellite imagery, the Tokyo VAAC reported that on 19 July a possible eruption produced a plume that rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted SW. Ash was noted and then later dissipated. A possible eruption was reported the next day, and again a subsequent satellite image showed that ash had dissipated within a few hours. The Aviation Color Code level remained at Orange.

KVERT reported that during 2-9 July seismic activity from Karymsky was above background levels and suggested that possible ash plumes rose to an altitude of 2 km (6,500 ft) a.s.l. A thermal anomaly was detected in satellite imagery on most days; cloud cover occasionally prevented views of the volcano. On 7 July ash plumes drifted 20 km S. Based on information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 13 July an ash plume rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted W. The Aviation Color Code level remained at Orange.

KVERT reported that during 25 June-2 July seismic activity from Karymsky was above background levels and suggested that possible ash plumes rose to an altitude of 7 km (23,000 ft) a.s.l. A strong thermal anomaly was detected in satellite imagery on 27 June; cloud cover prevented views of the volcano on other days. The Aviation Color Code level remained at Orange.

Based on analysis of satellite imagery, KVERT reported a thermal anomaly over the volcano during 17, 19-20, and 22-23 June. Small ash clouds 10 x 8 km and 12 x 5.5 km in dimension were seen E of the volcano on 17 and 23 June, respectively. Based on information from KEMSD, the Tokyo VAAC reported that an eruption on 29 June produced a plume that rose to an altitude of 7 km (23,000 ft) a.s.l. Ash was not identified on satellite imagery. The Aviation Color Code level remained at Orange.

KVERT reported that during 11-18 June seismic activity from Karymsky was above background levels. Seismic data suggested that possible ash plumes rose to an altitude of 5.2 km (17,000 ft) a.s.l. during 10-12 June and to an altitude of 3.9 km (12,800 ft) a.s.l. on 16 June. Satellite imagery analysis revealed ash plumes that drifted about 195 km E on 10 and 11 June and a thermal anomaly over the volcano on 11, 15, and 16 June. Small ash clouds drifted 22 km E on 17 June. The Aviation Color Code level remained at Orange.

KVERT reported that during 4-11 June seismic activity from Karymsky was above background levels, and suggested that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. on 6 June. Satellite imagery revealed a thermal anomaly over the volcano during 4-5 and 8 June. Based on information from KVERT and Yelizovo Airport (UHPP), and analyses of satellite imagery, the Tokyo VAAC reported that on 11 June an eruption produced an ash plume that rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted NE and SE. The Aviation Color Code level remained at Orange.

KVERT reported that during 14-21 May seismic activity from Karymsky was above background levels, suggesting that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. Satellite imagery revealed a thermal anomaly over the volcano during 13-17 and 19-20 May, and an ash plume that drifted 18 km NE on 17 May. Based on information from the Yelizovo Airport (UHPP) and KVERT, the Tokyo VAAC reported that on 22 and 25 May ash plumes rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted SW and W. The Aviation Color Code level remained at Orange.

KVERT reported that during 7-14 May seismic activity from Karymsky was above background levels, suggesting that possible ash plumes rose to altitudes of 2-4.6 km (6,600-15,100 ft) a.s.l. Satellite imagery revealed a thermal anomaly over the volcano during 8 and 11-13 May. The Aviation Color Code level remained at Orange.

KVERT reported that during 23-30 April seismic activity from Karymsky was above background levels, suggesting that possible ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. Volcanologists working in the area on 20 and 21 April saw gas-and-steam plumes containing some ash rise to an altitude of 3 km (10,000 ft) a.s.l. At night, Strombolian activity was occasionally observed. Satellite imagery revealed a daily thermal anomaly over the volcano. The Aviation Color Code level remained at Orange.

KVERT reported that on 16 and 23 April seismic activity from Karymsky was at background levels. During 17-22 April, seismicity was above background levels and a thermal anomaly was seen in satellite imagery. On 17 and 18 April, seismic data suggested that ash plumes rose to an altitude of 2 km (6,500 ft) a.s.l. Ash plumes were seen in satellite imagery drifting 40-130 km SE on 17 and 21 April. The Aviation Color Code level remained at Orange.

KVERT reported that seismic activity from Karymsky was above background on 11 and 13-15 April. Satellite imagery revealed a thermal anomaly from the volcano during 11-12 April. The Aviation Color Code level remained at Orange.

KVERT reported that seismic activity from Karymsky was above background on 2 and 3 April and at background levels during 4-9 April. Satellite imagery revealed a thermal anomaly from the volcano during 3-4 and 6 April. The Aviation Color Code level remained at Orange.

KVERT reported that seismic activity from Karymsky increased on 25 March. Two days later, an intense thermal anomaly over the volcano was seen in satellite imagery. During 28-29 March ash plumes were seen in the area of the volcano. The Aviation Color Code level was raised to Orange.

KVERT reported that during 5-12 March seismic activity from Karymsky was slightly above background levels, possibly indicating weak ash explosions. A weak daily thermal anomaly was detected in satellite imagery. Based on information from KEMSD, the Tokyo VAAC reported that an eruption on 12 March produced a plume that rose to an altitude of 5.8 km (19,000 ft) a.s.l. Ash was not identified on satellite imagery. The Level of Aviation Color Code remained at Yellow.

KVERT reported that seismic activity from Karymsky was above background levels during 11-14 February, possibly indicating weak ash explosions. Analyses of satellite imagery revealed a thermal anomaly over the volcano during that time and also on 15 February. Seismic activity was at background levels during 15-19 February. The Aviation Color Code level remained at Orange.

KVERT reported that during 5-12 February seismic activity from Karymsky was above background levels and possibly indicated weak ash explosions. Analyses of satellite imagery revealed a thermal anomaly over the volcano on 8 February; meteorological clouds prevented observations on other days. The Aviation Color Code level remained at Orange.

KVERT reported that during 29 January-5 February seismic activity from Karymsky was above background levels and possibly indicated weak ash explosions. Analyses of satellite imagery revealed a thermal anomaly over the volcano on 28 January and 1 February. The Level of Aviation Color Code remained at Orange.

KVERT reported that during 22-29 January seismic activity from Karymsky was above background levels and possibly indicated weak ash explosions. Analyses of satellite imagery revealed a thermal anomaly over the volcano during 21-25 and 27 January. The Level of Aviation Color Code remained at Orange.

KVERT reported that during 15-22 January seismic activity from Karymsky was above background levels, possibly indicating that ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. Analyses of satellite imagery revealed a daily thermal anomaly over the volcano. The Level of Aviation Color Code remained at Orange.

KVERT reported that during 8-15 January seismic activity from Karymsky was above background levels, possibly indicating that ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. Analyses of satellite imagery revealed an almost daily thermal anomaly over the volcano and ash plumes that drifted 113 km SE on 12 and 13 January. The Level of Aviation Color Code remained at Orange.

KVERT reported that a thermal anomaly over Karymsky was detected in satellite imagery during 30-31 December 2009, 1 January and 4-7 January 2010. Seismic activity was above background levels during 1-8 January. The Level of Aviation Color Code remained at Orange.

KVERT reported that a thermal anomaly over Karymsky was detected in satellite imagery during 24-26 and 29-30 December. Gas-and-steam bursts were seen by volcanologists on 28 December. The Level of Aviation Color Code remained at Orange.

KVERT reported that during 18-25 December a thermal anomaly over Karymsky was detected in satellite imagery. Seismic data were not available due to technical problems. Based on information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 25 December an ash plume rose to an altitude of 6.7 km (22,000 ft) a.s.l. and drifted SE. KVERT noted three linear areas of ash deposits 10 km SE of Karymsky. The Level of Aviation Color Code remained at Orange.

KVERT reported that during 11-13 and 17 December a thermal anomaly over Karymsky was detected in satellite imagery. Seismic activity was above background levels on 12 and 13 December; data were not available during 11-21 December due to technical problems. The Level of Aviation Color Code remained at Orange.

KVERT reported that analyses of satellite imagery revealed a thermal anomaly from Karymsky during 3 and 6-7 December; ash deposits extended 45 km SE on 6 December. A new lava flow was seen on the S flank on 8 December. Seismic data were seldom available due to technical problems. The Level of Aviation Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 27-30 November and 1 December; data were not available during 2-4 December due to technical problems. Analyses of satellite imagery revealed a daily thermal anomaly and ash plumes that drifted 165 km E during 29-30 November and 1-2 December. The Level of Aviation Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels on 23 and 25 November; data were not available on the other days during 20-27 November due to technical reasons. Elevated seismicity possibly indicated that ash plumes rose to an altitude of 3.8 km (12,500 ft) a.s.l. Analyses of satellite imagery revealed a daily thermal anomaly and ash plumes that drifted 120 km E on 23 and 25 November. The Level of Aviation Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels on 12, 14, and 16 November; data were not available on the other days during 13-20 November due to technical reasons. Elevated seismicity possibly indicated that ash plumes rose to an altitude of 3 km (9,900 ft) a.s.l. Analyses of satellite imagery revealed a daily thermal anomaly and ash plumes that drifted 130 km E during 12-14 and 17 November. The Level of Aviation Color Code remained at Orange. Based on information from KEMSD, the Tokyo VAAC reported that on 23 November an eruption produced a plume that rose to an altitude of 4 km (13,000 ft) a.s.l.

KVERT reported that seismic activity at Karymsky was above background levels during 5-9 November, a possible indication that ash plumes rose to an altitude of 3.7 km (12,100 ft) a.s.l. Analyses of satellite imagery during 5-12 November revealed almost daily thermal anomalies and ash plumes that drifted 190 km E during 8-12 November. The Level of Aviation Color Code remained at Orange. Based on information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 14 November an ash plume rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted E.

KVERT reported that seismic activity at Karymsky was above background levels during 29-31 October; data was not collected during 1-4 November due to technical reasons. Seismic signals possibly indicated that ash plumes rose to an altitude of 3.7 km (12,100 ft) a.s.l. on 31 October and 5 November. Analyses of satellite imagery during 29 October-5 November revealed almost daily thermal anomalies and intermittent ash plumes that drifted 180 km E. The Level of Aviation Color Code remained at Orange. Based on information from KEMSD, the Tokyo VAAC reported that eruptions on 8 and 10 November produced plumes that rose to altitudes of 3-3.4 km (10,000-11,000 ft) a.s.l. Ash was not identified on satellite imagery.

KVERT reported that seismic activity at Karymsky was above background levels during 23-27 and 30 October, a possible indication that ash plumes rose to an altitude of 3.7 km (12,100 ft) a.s.l. No seismic data was available on 22 and 28 October. Analyses of satellite imagery revealed an ash plume that drifted 120 km E on 23 October, and a thermal anomaly during 23-26 and 29 October. The Level of Aviation Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 16-23 October and possibly indicated that ash plumes rose to an altitude of 3.9 km (12,800 ft) a.s.l. The Level of Aviation Color Code remained at Orange. Based on information from KEMSD, the Tokyo VAAC reported that eruptions during 24-25 October produced plumes that rose to altitudes of 3.4-3.7 km (11,000-12,000 ft) a.s.l. Ash was not identified on satellite imagery.

KVERT reported that seismic activity at Karymsky was elevated above background levels during 9-16 October and possibly indicated that ash plumes rose to an altitude of 3.7 km (12,100 ft) a.s.l. On 12 October, volcanologists doing fieldwork saw an ash plume rise to an altitude of 3.5 km (11,500 ft) a.s.l. The Level of Aviation Color Code remained at Orange. Based on information from KEMSD, the Tokyo VAAC reported that on 20 October eruptions produced plumes that rose to altitudes of 3-3.7 km (10,000-12,000 ft) a.s.l. Ash was not identified on satellite imagery.

KVERT reported that seismic activity at Karymsky was above background levels during 2-9 October and possibly indicated weak ash explosions. On 7 October, field scientists saw an ash plume that rose to an altitude of 3.5 km (11,500 ft) a.s.l. and drifted SSE. The Level of Aviation Color Code remained at Orange. Based on information from KEMSD, the Tokyo VAAC reported that on 9 October an eruption produced a plume that rose to an altitude of 3 km (10,000 ft) a.s.l.

KVERT reported that seismic activity at Karymsky was elevated above background levels during 25 September-2 October and possibly indicated weak ash explosions. Analyses of satellite imagery revealed a weak thermal anomaly over the lava dome on 28 September; cloud cover prevented observations on the other days. Scientists saw fumarolic activity during an overflight on 1 October. The Level of Aviation Color Code remained at Orange.

KVERT reported that on 17 and 22 September a weak thermal anomaly over Karymsky was detected in satellite imagery. During 19-23 September seismic activity was above background levels; analyses of the seismic data indicated that ash plumes possibly rose to an altitude of 2 km (6,600 ft) a.s.l. during 21-22 September, and to an altitude of 4.5 km (14,800 ft) a.s.l. on 23 September. Scientists flying near Karymsky in a helicopter on 22 September saw ash plumes that rose to an altitude of 1.7 km (5,600 ft) a.s.l. and drifted E. The Level of Aviation Color Code was raised to Orange.

KVERT reported that seismic activity at Karymsky was slightly above background levels on 20 and 21 August and at background levels during 22-31 August. Analysis of satellite imagery revealed a small thermal anomaly over the volcano on 21 August. The Level of Concern Color Code was lowered to Green on 31 August.

Based on information from KEMSD, the Tokyo VAAC reported that on 6 June an eruption from Karymsky produced a plume that rose to an altitude of 3.4 km (11,000 ft) a.s.l. Ash was not identified on satellite imagery.

KVERT reported that fumarolic activity from Karymsky was seen by volcanologists during 17-24 April. Analysis of satellite imagery revealed a thermal anomaly on the volcano on 17 April. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was not analyzed during 9-17 April due to technical reasons. Cloud cover prevented observations on the other days. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels on 2 and 3 April and at background levels on 4 April; no data was collected during 5-10 April due to technical reasons. Analysis of satellite imagery revealed a weak thermal anomaly on the volcano on 5 April. Fumarolic activity was seen by volcanologists on 9 April. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 27 March-3 April. A thermal anomaly on the volcano was seen in satellite imagery on 31 March. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was elevated during 19-22 March and at background levels during 23-24 March. Based on interpretations of seismic data, ash plumes likely rose to an altitude of 2 km (6,600 ft) a.s.l. On 26 March, ash deposits extending 30 km S of the volcano were seen on satellite imagery. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels on 12 and 18 March; no data was collected during 13-17 March due to technical reasons. According to reports from Yelizovo Airport, pilots saw an ash plume that rose to an altitude of 3.9 km (12,800 ft) a.s.l. and drifted E on 12 March. Analysis of satellite imagery revealed a thermal anomaly on the lava dome during 12-14 and 16-17 March, and ash plumes that drifted 200 km in easterly directions during 12-13 and 16-17 March. The Level of Concern Color Code remained at Orange.

Based on information from the Yelizovo Airport, the Tokyo VAAC reported that on 19 March an ash plume rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted W.

KVERT reported that seismic activity at Karymsky was at background levels during 6-13 March. Based on interpretations of seismic data, ash plumes likely rose to an altitude of 3 km (10,000 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly on the lava dome during 6-12 March, and ash plumes that drifted in multiple directions during the reporting period. The Level of Concern Color Code remained at Orange.

Based on information from KVERT and pilot observations, the Tokyo VAAC reported that on 13 March an ash plume rose to an altitude of 4 km (13,000 ft) a.s.l. and drifted E.

KVERT reported that seismic activity at Karymsky was at background levels during 27 February-6 March. Based on interpretations of seismic data, ash plumes likely rose to an altitude of 3.5 km (11,500 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly on the lava dome during 27-28 February and 1-4 March, and an ash plume that drifted 120 km SE on 4 March. Ash deposits on the volcano were noted. On 3 March, pilots reported an ash plume that rose to an altitude of 3.5 km (11,500 ft) a.s.l. and drifted E. The Level of Concern Color Code remained at Orange.

Based on information from KEMSD and analysis of satellite imagery, the Tokyo VAAC reported that an eruption on 6 March produced a plume that rose to an altitude of 3 km (10,000 ft) a.s.l.

KVERT reported that seismic activity at Karymsky was at background levels during 21-28 February. Based on interpretations of seismic data, ash plumes likely rose to an altitude of 3.7 km (12,100 ft) a.s.l. On 24 February, pilots reported a dark plume near the volcano that rose to altitudes of 2.1 km (6,900 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly on the lava dome during 21 and 24-25 February, and an ash plume that drifted 150 km NE on 21 February. The Level of Concern Color Code remained at Orange.

Based on information from KEMSD and analysis of satellite imagery, the Tokyo VAAC reported that eruptions on 28 and 29 February produced plumes that rose to altitudes of 3-3.4 km (10,000-11,000 ft) a.s.l. and drifted W. On 3 March, an ash plume reported by the Yelizovo Airport (UHPP) rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted E.

KVERT reported that during 13-20 January seismic data from Karymsky was unavailable and clouds prevented satellite image observations. The Level of Concern Color Code remained at Orange. Based on information from KEMSD and observations of satellite imagery, the Tokyo VAAC reported that during 21-22 February eruptions produced plumes that rose to altitudes of 3-4.3 km (10,000-14,000 ft) a.s.l.

KVERT reported that seismic activity at Karymsky was above background levels during 6-9 February and at background levels during 10-13 February. Ash explosions produced plumes that rose to an altitude of 2.5 km (8,200 ft) a.s.l. Clouds prevented satellite observations. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 1-4 February and at background levels on the other days during 30 January-6 February. Analysis of satellite imagery revealed a weak thermal anomaly in the crater on 30 January; clouds prohibited views during the rest of the reporting period. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was at background levels during 23-30 January. Analysis of satellite imagery revealed a weak thermal anomaly in the crater on 23 and 24 January; clouds prevented observations on other days. The Level of Concern Color Code remained at Orange.

Based on information from KVERT and KEMSD, the Tokyo VAAC reported that during 2-3 February eruptions produced plumes that rose to altitudes of 3.4-3.7 km (11,000-12,000 ft) a.s.l. Ash was not identified on satellite imagery.

KVERT reported that seismic activity at Karymsky was above background levels on 15 January and at background levels during 16-23 January. Weak ash-and-gas explosions possibly occurred on 15 January. Analysis of satellite imagery revealed a thermal anomaly in the crater during 18-19 and 21 January. The Level of Concern Color Code remained at Orange.

KVERT reported that during 10-14 January seismic activity at Karymsky was above background levels and ash-and-gas explosions possibly occurred; seismic activity was not evaluated on 8 and 9 January due to technical issues. Analysis of satellite imagery revealed a thermal anomaly in the crater during 8-12 and 14-15 January. Gas-and-steam plumes drifted 25 km SE and NE on 8 and 12 January.

Based on analysis of satellite imagery and information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 16 January an ash plume rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted SE.

KVERT reported that during 2-9 January seismic activity from Karymsky was not evaluated due to technical issues. Analysis of satellite imagery revealed a thermal anomaly in the crater on 7 January; clouds prevented observations on the other days. The Level of Concern Color Code remained at Orange.

KVERT reported during 26 December-2 January seismic activity from Karymsky was not evaluated due to technical issues. Clouds prevented satellite observations of the volcano. The Level of Concern Color Code remained at Orange.

KVERT reported that on 18 and 20 December seismic activity at Karymsky was at background levels; possible explosions may have generated ash-and-gas plumes to an altitude of 3 km (9,800 ft) a.s.l. on 18 December. Analysis of satellite imagery revealed a thermal anomaly in the crater during 21-26 December and ash plumes that drifted 80 km E during 21-23 December. Ash deposits 26 km long to the SE and 9 km long to the NE were noted on 21 December. The Level of Concern Color Code remained at Orange.

KVERT reported that during 12-19 December seismic activity at Karymsky was at background levels; possible explosions may have generated ash-and-gas plumes to an altitude of 2.5 km (8,200 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly in the crater during 12-14 and 17 December and an ash plume that drifted 240 km SE on 16 December. The Level of Concern Color Code remained at Orange.

KVERT reported that during 5 and 9-10 December seismic activity at Karymsky was at background levels; possible explosions may have generated ash-and-gas plumes to an altitude of 2.8 km (9,200 ft) a.s.l. Volcanologists occasionally saw ash plumes rise to altitudes of 2 km (6,600 ft) a.s.l. and drift E. Ash deposits on the E flank were more than 5 km long. Analysis of satellite imagery revealed a thermal anomaly in the crater on 8 December and an ash plume that drifted ESE. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was at background levels during 27-30 November; possible explosions may have generated ash-and-gas plumes to an altitude of 3.7 km (12,100 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly in the crater during 27-29 November and 1 December. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was at background levels during 21-23 and 26-28 November. Seismicity increased above background levels on 24 and 25 November; possible explosions may have generated ash plumes to an altitude of 3 km (10,000 ft) a.s.l. during 23-25 November. During an overflight, scientists observed gas-and-steam plumes that rose to altitudes of 2-2.4 km (6,600-7,900 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly in the crater during 20, 22, and 24-26 November. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky increased above background levels during 13-17 November; possible explosions may have generated ash plumes to an altitude of 3.3 km (10,800 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly in the crater during 13-16 November and an ash plume that drifted 28 km E on 15 November. Clouds prevented observations on the other days during 14-21 November. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky increased above background levels during 11-12 November. On 10 November, ash plumes were seen on satellite imagery drifting 38 km E and 28 km ENE. During 10-11 November, possible explosions may have generated ash plumes to an altitude of 3.8 km (12,500 ft) a.s.l. Also during 10-11 November, analysis of satellite imagery revealed a thermal anomaly in the crater; clouds prevented observations on the other days. The Level of Concern Color Code remained at Orange.

Based on analysis of satellite imagery, information from the Yelizovo Airport (UHPP), and KEMSD notices, the Tokyo VAAC reported that an ash plume rose to an altitude of 2.7 km (9,000 ft) a.s.l. on 12 November. On 12 and 15 November, eruptions generated plumes that rose to an altitude of 3.4 km (11,000 ft) a.s.l.

KVERT reported that seismic activity at Karymsky was above background levels during 31 October and 2-3 November and at background levels on the other days during 1-7 November. Possible explosions on 31 October, and 2 and 3 November may have generated ash plumes to an altitude of 3.8 km (12,500 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly in the crater on 31 October, and 2 and 6 November; clouds prevented observations on the other days. The Level of Concern Color Code remained at Orange.

Based on analysis of satellite imagery and information from KEMSD, the Tokyo VAAC reported that an eruption generated a plume to an altitude of 3.7 km (12,000 ft) a.s.l. on 11 November.

KVERT reported that seismic activity at Karymsky was above background levels during 24-27 October and at background levels during 28-31 October. Possible explosions may have generated ash plumes to an altitude of 2.8 km (9,200 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly in the crater on 23, 24, and 28 October; clouds prevented observations on the other days. The Level of Concern Color Code remained at Orange.

Based on analysis of satellite imagery and information from KEMSD, the Tokyo VAAC reported that an eruption generated a plume to an altitude of 4 km (13,000 ft) a.s.l. on 2 November.

KVERT reported that seismic activity at Karymsky was above background levels on 17 and 20 October and at background levels on the other days during 18-24 October. Possible explosions may have generated ash plumes to an altitude of 3.2 km (10,500 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly in the crater on 17, 19, and 21 October; clouds prevented observations on the other days. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 10-17 October. Possible explosions may have generated ash plumes to an altitude of 3.1 km (10,200 ft) a.s.l. Analysis of satellite imagery on 13 October revealed a thermal anomaly in the crater and an ash plume about 5 km wide that drifted 32 km NNE. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 3-10 October. Possible explosions during 4-9 October may have generated ash plumes to an altitude of 4 km (13,100 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly in the crater during 3-4 and 8-9 October and cloudy conditions on the other days. The Level of Concern Color Code remained at Orange.

Based on analysis of satellite imagery and information from KEMSD, the Tokyo VAAC reported that an eruption generated a plume to an altitude of 3.4 km (11,000 ft) a.s.l. on 11 October.

KVERT reported that seismic activity at Karymsky was above background levels during 26 September-3 October. Possible explosions during 25-27 September and 1-2 October may have generated ash plumes to an altitude of 3.3 km (10,800 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly in the crater on 29 September and cloudy conditions on the other days. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 19-26 September. Possible daily explosions may have generated ash plumes to an altitude of 3.8 km (12,500 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly in the crater on 18 and 23 September. The Level of Concern Color Code remained at Orange.

Based on analysis of satellite imagery and information from KEMSD, the Tokyo VAAC reported that eruptions generated plumes to altitudes of 3-3.4 km (10,000-11,000 ft) a.s.l. on 24 and 28 September.

KVERT reported that seismic activity at Karymsky was above background levels during 12-19 September. Possible daily explosions may have generated ash plumes to an altitude of 3.2 km (10,500 ft) a.s.l. Analysis of satellite imagery revealed that ash plumes drifted more than 80 km SE on 15 and 16 September and a thermal anomaly was present in the crater during 13 and 15-17 September. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 5-12 September. Possible explosions may have generated ash plumes to an altitude of 3.2 km (10,500 ft) a.s.l. Analysis of satellite imagery revealed ash plumes drifting SE on 6 September and a thermal anomaly in the crater during 6-7 September. The Level of Concern Color Code remained at Orange.

Based on analysis of satellite imagery, information from KVERT, and pilot reports, the Tokyo VAAC reported that on 16 September an ash plume rose to an altitude of 3 km (10,000 ft) a.s.l.

KVERT reported that seismic activity at Karymsky was above background levels during 29 August-5 September. Possible explosions may have generated ash plumes to an altitude of 3.8 km (12,500 ft) a.s.l. Analysis of satellite imagery revealed ash plumes drifting SE on 29 August and a thermal anomaly in the crater during 29-31 August. The Level of Concern Color Code remained at Orange.

Based on analysis of satellite imagery, the Tokyo VAAC reported that on 7 September an ash plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted E.

KVERT reported that seismic activity at Karymsky was at background levels during 21-23 August and above background levels during 24-27 August. Possible explosions may have generated ash plumes to an altitude of 3.2 km (10,500 ft) a.s.l. Analysis of satellite imagery revealed a thermal anomaly in the crater during 24 and 26-28 August and that an ash plumes drifted SE on 27 August. The Level of Concern Color Code remained at Orange.

Based on analysis of satellite imagery and information from KEMSD, the Tokyo VAAC reported that on 29 August and 2 September eruption plumes rose to an approximate altitude of 3 km (10,000 ft) a.s.l.

KVERT reported that seismic activity at Karymsky was at typical levels during 14-15, 17, and 19-20 August. They also reported possible explosions during 14-15 and 17-20 August. Volcanic tremor was detected on 14 and 20 August. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was at background levels on 9 and 13 August and slightly above background levels on the other days during 8-15 August. Based on interpretations of seismic data, possible ash plumes rose to an altitude of 3.1 km (10,200 ft) a.s.l. on 8, 10, 11, and 14 August. Analysis of satellite imagery revealed a thermal anomaly in the crater on 11 August; clouds inhibited views on other days. The Level of Concern Color Code remained at Orange.

Based on analysis of satellite imagery and information from KEMSD, the Tokyo VAAC reported that on 14 August an eruption plume rose to an altitude of 2.7 km (9,000 ft) a.s.l.

KVERT reported that seismic activity at Karymsky was above background levels during 1-8 August and possibly indicated that explosions produced ash plumes to an altitude of 3.1 km (10,200 ft) a.s.l. Observations of satellite imagery revealed a thermal anomaly in the crater on 2 August; clouds inhibited views on other days. The Level of Concern Color Code remained at Orange.

Based on observations of satellite imagery and information from KEMSD, the Tokyo VAAC reported that on 11 August an eruption plume rose to an altitude of 3.4 km (11,000 ft) a.s.l.

KVERT reported that seismic activity at Karymsky was above background levels during 25 July-1 August and possibly indicated that explosions produced ash plumes to an altitude of 3.7 km (12,100 ft) a.s.l. According to area volcanologists and pilots, ash plumes rose to altitudes of 5-6 km (16,400-19,700 ft) a.s.l. on 25 July. Observations of satellite imagery revealed a daily thermal anomaly in the crater. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels on 18, 19, and 23 July and at background levels during 20-22 and 24-25. Explosive activity that produced ashfall was seen by area volcanologists. Interpretation of the seismic data suggested that on 19, 21, and 23 July possible ash-and-gas plumes rose to altitudes of 3 km (10,000 ft) a.s.l. Observations of satellite imagery revealed a thermal anomaly in the crater during 19-21 July. The Level of Concern Color Code was raised to Orange.

Based on information from the Yelizovo Airport (UHPP), the Tokyo VAAC reported that on 25 July an ash plume rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted NE.

KVERT reported that seismic activity at Karymsky was at background levels during 20-27 June but may have indicated weak explosions daily. Observations of satellite imagery revealed a thermal anomaly in the crater on 20 and 25 June. The Level of Concern Color Code was lowered to Yellow.

KVERT reported that seismic activity at Karymsky was at background levels during 13-20 June but may have indicated weak explosions daily. Observations of satellite imagery revealed a thermal anomaly in the crater on 12 June; clouds obscured views on other days during the reporting period. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was slightly above background levels on 6 June and at background during 7-13 June. Gas-and-ash explosions that produced plumes to an altitude of 2.6 km (8,500 ft) a.s.l. may have occurred on 6 June. Observations of satellite imagery revealed thermal anomalies in the crater on 6, 7, and 11 June. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was slightly above background levels during 1-4 June and at background levels the other days during 30 May-6 June. Gas-and-ash explosions that produced plumes to an altitude of 2.3 km (7,500 ft) a.s.l. may have occurred during days of slightly elevated seismicity. Observations of satellite imagery revealed thermal anomalies in the crater during 1-4 June and a gas-and-steam plume that drifted 61 km SE on 2 June. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was slightly above background levels during 22, 25-26, and 28 May and at background levels the other days during 23-30 May. Gas-and-ash explosions that produced plumes to an altitude of 3.4 km (11,200 ft) a.s.l. may have occurred during days of slightly elevated seismicity. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was slightly above background levels on 15, 16, and 21 May and at background levels the other days during 16-23 May. Gas-and-ash explosions that produced plumes to an altitude of 3.4 km (11,200 ft) a.s.l. may have occurred during 15-16 and 21-22 May. Observations of satellite imagery revealed that on 16 and 20 May a thermal anomaly was present in the crater. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels on 11 and 12 May and at background levels the other days during 9-16 May. Gas-and-ash explosions that produced plumes to an altitude of 3.1 km (10,200 ft) a.s.l. may have occurred on 11 and 12 May. Observations of satellite imagery revealed that on 13 May a thermal anomaly was present in the crater and a steam plume drifted 7 km ESE. An ash plume at an altitude of 2 km (6,600 ft) a.s.l. was spotted on 15 May and drifted E. The Level of Concern Color Code remained at Orange.

Based on observations of sateliite imagery, the Tokyo VAAC reported that on 20 May an eruption plume rose to an altitude of 3.4 km (11,000 ft) a.s.l.

KVERT reported that seismic activity at Karymsky was slightly above background levels on 3 and 7 May and at background levels the other days during 2-9 May; gas-and-ash explosions may have occurred on 3 and 7 May. Based on pilot observations, an ash plume rose to an altitude of about 5 km (16,400 ft) a.s.l. on 6 May. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was at background levels during 25 April-2 May. Possible activity was characterized by gas-and-ash plumes that rose to altitudes of 2-2.5 km (6,600-8,200 ft) a.s.l. Based on seismic interpretation, a gas-and-ash explosion may have occurred on 26 April. Observations of satellite imagery revealed that a thermal anomaly was present in the crater on 25, 27, and 28 April. Based on airport data and information from KEMSD, the Tokyo VAAC reported that an eruption plume rose to altitudes of 3.7 km (10,000-17,000 ft) a.s.l. during 6-7 May. Ash was not detected on satellite imagery. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 18-25 April. Observations of satellite imagery revealed that a thermal anomaly was present in the crater on 18 and 21 April. Based on seismic interpretation, weak ash-and-gas explosions may have occurred on 20 and 21 April and produced plumes to altitudes of 2.6-3.4 km (8,500-11,200 ft) a.s.l. Volcanologists reported seeing ash plumes to an altitude of 2 km (6,700 ft) a.s.l. during 20-23 April. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 11-18 April. Based on seismic interpretation, weak ash-and-gas explosions or hot avalanches may have occurred daily during 10-14. Observations of satellite imagery revealed that a thermal anomaly was present in the crater on 12 and 13 April. Based on information from KEMSD, the Tokyo VAAC reported that an eruption plume rose to an altitude of 3.7 km (12,000 ft) a.s.l. on 22 April. Ash was not detected on satellite imagery. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 4-11 April. Based on seismic interpretation, weak ash-and-gas explosions or hot avalanches may have occurred daily during the reporting period. Observations of satellite imagery revealed that a thermal anomaly was present in the crater during 4-6 April and an ash plume drifted 70-80 km ESE on 8 April. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 28-29 March and slightly above background levels during 30 March-4 April. Pilots observed ash plumes to altitudes of 5-7 km (16,400-23,000 ft) a.s.l. during 28-29 March. Based on seismic interpretation, ash plumes possibly rose to an altitude of 2.5 km (8,200 ft) a.s.l. on 2 April and weak ash explosions or avalanches may have occurred daily during the reporting period. Observations of satellite imagery revealed that a thermal anomaly was present in the crater on 28 March and 1, 2, and 3 April; an ash plume drifted S on 3 April. Ash deposits were noted in areas about 20 km E, 70 km SW, and 45-50 km S. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was slightly above background levels during 23 and 25-26 March, and at background levels during 21-22, 24, and 27-28 March. Based on seismic interpretation, ash plumes possibly rose to an altitude of 3.3 km (10,800 ft) a.s.l. on 22 March. Weak ash explosions or avalanches possibly occurred during 23-26 March. Based on observations of satellite imagery and information from KVERT, the Tokyo VAAC reported that eruption plumes rose to altitudes of 3-7 km (10,000-23,000 ft) a.s.l. during 28-29 March. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was slightly above background levels during 13-16 March and at background levels during 17-19 March. Weak ash explosions or avalanches possibly occurred on 15 March when observations of satellite imagery revealed an ash plume drifting 40 km SE. On 16 March, ash deposits 15-20 km in length mantled the snow to the NE and ESE. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was slightly above background levels during 7-14 March. Observations of satellite imagery revealed that a weak thermal anomaly was present in the crater on 9 and 12 March. On 13 March, an ash plume rose to an altitude of 2.5 km (8,200 ft) a.s.l. Ash deposits on the snow about 3-4 km SE of the summit were observed on satellite imagery. The Level of Concern Color Code was raised from Yellow to Orange.

KVERT reported that seismic activity at Karymsky was slightly above background levels during 30 November-7 December. A decrease in activity based on observations of satellite imagery during November and December 2007 prompted KVERT to lower the Level of Concern Color Code to Yellow on 7 December.

KVERT reported that seismic activity at Karymsky was at background levels during 24-25 November and slightly above background levels on 26 November. Seismic data was unavailable on the other days during 23-30 November. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 1-5 November and at background levels during 6-9 November. Based on seismic interpretation, ash explosions occurred and an ash plume may have risen to an altitude of 5 km (16,400 ft) a.s.l. on 2 November. Observations of satellite imagery revealed that a small thermal anomaly was present at the summit on 6 November; cloud cover obscured observations on other days. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 25-28 October and at background levels during 29 October-2 November. Based on seismic interpretation, ash explosions occurred. Cloud cover obscured observations of satellite imagery. The Level of Concern Color Code remained at Orange.

Based on information from KEMSD, the Tokyo VAAC reported that an eruption plume rose to an altitude of 5.2 km (17,000 ft) a.s.l. during 18-21 October. Ash was not detected on satellite imagery.

KVERT reported that seismic activity at Karymsky was above background levels during 19-26 October. Based on seismic interpretation, ash plumes may have risen to an altitude of 3.5 km (11,500 ft) a.s.l. during the reporting period. Observations of satellite imagery revealed that a thermal anomaly was present in the crater during 19-20 and 22-24 October, and ash plumes drifted SE and S during 19-20 and 24 October.

KVERT reported that seismic activity at Karymsky was above background levels during 12-19 October. Based on seismic interpretation, ash plumes may have risen to an altitude of 4.3 km (14,100 ft) a.s.l. during the reporting period. Observations of satellite imagery revealed that a thermal anomaly was present in the crater during 14-18 October and ash plumes drifted E during 15-18 October. The Level of Concern Color Code remained at Orange.

KVERT reported that seismic activity at Karymsky was above background levels during 5-12 October. Based on seismic interpretation, ash plumes may have risen to an altitude of 5.2 km (17,100 ft) a.s.l. during the reporting period. Observations of satellite imagery revealed that a thermal anomaly was present in the crater and ash plumes drifted E during 4-8 and 10-11 October. The Level of Concern Color Code remained at Orange.

Based on pilot reports and observations of satellite imagery, the Tokyo VAAC reported that ash plumes rose to altitudes of 4.6-5.2 km (15,000-17,100 ft) a.s.l. on 12 and 16 October. Plumes drifted SE and E.

KVERT reported that seismic activity at Karymsky was above background levels during 28 September-5 October. Based on seismic interpretation, ash plumes may have risen to an altitude of 3.5 km (11,500 ft) a.s.l. during the reporting period. Observations of satellite imagery revealed that a thermal anomaly was present in the crater during 27 and 29-30 September and 1 and 3 October. Ash plumes drifted SE and E on 30 September and 1 and 3 October. The Level of Concern Color Code remained at Orange.

Based on information from KEMSD and KVERT, observations in the Petropavlovsk-Kamchatsky Flight Information Region (FIR), and pilot reports, the Tokyo VAAC reported that ash plumes rose to an altitude of 3-3.7 km (10,000-12,000 ft) a.s.l. on 5, 7, and 8 October. Plumes drifted E and NE.

KVERT reported that seismic activity at Karymsky was above background levels during 21-28 September. Based on seismic interpretation, ash plumes may have risen to an altitude of 3.5 km (11,500 ft) a.s.l. during 20, 22, and 24-26 September. Observations of satellite imagery revealed that a thermal anomaly was present in the crater during 20-21 and 24-26 September and ash plumes drifted E during 24-27 September. The Level of Concern Color Code remained at Orange.

Based on information from KEMSD and pilot reports, the Tokyo VAAC reported that ash plumes rose to an altitude of 3.7 km (12,000 ft) a.s.l. on 28 September and 4.3 km (14,000 ft) a.s.l. on 2 October.

KVERT reported that seismic activity at Karymsky was above background levels during 14-21 September. Observations of satellite imagery revealed that ash plumes drifted SE on 15 September and a thermal anomaly was present in the crater during 13-15 and 17-19 September. Based on seismic interpretation, ash plumes may have risen to an altitude of 3.3 km (10,800 ft) a.s.l. during 15-16 and 20 September. The Level of Concern Color Code remained at Orange.

Based on pilot reports, information from KEMSD, observations of satellite imagery, and observations in the Petropavlovsk-Kamchatsky Flight Information Region (FIR), the Tokyo VAAC reported that ash plumes rose to altitudes of 4.6 km (15,000 ft) a.s.l. on 21 September and 3.4 km (11,000 ft) a.s.l. on 25 September.

KVERT reported that seismic activity at Karymsky was above background levels during 7-14 September. Based on seismic interpretation, ash plumes may have risen to an altitude of 3.5 km (11,500 ft) a.s.l. during the reporting period. Observations of satellite imagery revealed that ash plumes drifted E and SE during 7-10 September and a thermal anomaly was present in the crater during 8-10 and 11 September. The Level of Concern Color Code remained at Orange.

Based on information from KVERT, the Tokyo VAAC reported that ash plumes rose to an altitude of 3.4 km (11,000 ft) a.s.l. on 15 September. Ash was not identified on satellite imagery.

Seismic activity at Karymsky was above background levels during 31 August-7 September. Based on seismic interpretation, ash plumes may have risen to altitudes of 5.5-6 km (18,000-19,700 ft) a.s.l. Observations of satellite imagery revealed that a thermal anomaly was present in the crater during the reporting period. Ash plumes were also present and drifted NE on 31 August, and SE and NW during 1-3 September. The Level of Concern Color Code remained at Orange.

Based on information from KEMSD, pilot reports, and observations in the Petropavlovsk-Kamchatsky Flight Information Region (FIR), the Tokyo VAAC reported that ash plumes rose to altitudes of 3-7.3 km (10,000-24,000 ft) a.s.l. during 5-10 September. Ash was not identified on satellite imagery.

Seismic activity at Karymsky was above background levels during 24-31 August, with 100-280 shallow earthquakes occurring daily. Based on seismic interpretation, ash plumes may have risen to an altitude of 5.9 km (19,400 ft) a.s.l. Observations of satellite imagery revealed that a thermal anomaly was present in the crater on 24 and 30 August. Ash plumes were also present and drifted SE on 24 August and NE during 28-30 August. The Level of Concern Color Code remained at Orange.

Based on information from KEMSD, satellite imagery, observations in the Petropavlovsk-Kamchatsky Flight Information Region (FIR), and KVERT, the Tokyo VAAC reported that ash plumes rose to altitudes of 4.3-6.1 km (14,000-20,000 ft) a.s.l. during 31 August and 2-3 September. Ash was not identified on satellite imagery on 31 August.

Seismic activity at Karymsky was above background levels during 17-24 August, with 300-800 shallow earthquakes occurring daily. Based on seismic interpretation, ash plumes may have risen to an altitude of 5.7 km (18,700 ft) a.s.l. Observations of satellite imagery revealed that a thermal anomaly was present in the crater on 20 and 23 August. The Level of Concern Color Code remained at Orange.

Based on information from KEMSD, eruption plumes rose to estimated altitudes of 5.8 km and 4 km (19,000 ft and 13,000 ft) a.s.l. on 23 and 25 August, respectively. Ash was not identified on satellite imagery.

Seismic activity at Karymsky was above background levels during 10-17 August, with 350-600 shallow earthquakes occurring daily. Based on seismic interpretation, ash plumes may have risen to an altitude of 3 km (9,800 ft) a.s.l. The Level of Concern Color Code remained at Orange.

Seismic activity at Karymsky was above background levels during 3-10 August, with 300-800 shallow earthquakes occurring daily. Based on seismic interpretation, ash plumes may have risen to an altitude of 3 km (9,800 ft) a.s.l. The Level of Concern Color Code remained at Orange.

Seismic activity at Karymsky was above background levels during 27 July-3 August, with 150-600 shallow earthquakes occurring daily. Based on seismic interpretation, ash plumes may have risen to an altitude of 3 km (9,800 ft) a.s.l. Observations of satellite imagery revealed that a thermal anomaly was present in the crater on 31 July and 2 August and gas-and-steam plumes drifted SW on 2 August. The Level of Concern Color Code remained at Orange.

A KVERT report issued for Karymsky on 27 July stated the following, "The eruption of the volcano continues. Ash explosions up to 6 km (or 19,700 ft.) a.s.l. are possible at any time. The activity of the volcano could affect low-flying aircraft in the vicinity of the volcano."

Based on a report from unstated source and posted by the Tokyo VAAC, on 28 July ash plumes rose to estimated altitudes of ~6 km (20,000 ft) a.s.l., but the plume could not be identified in satellite analysis. The Level of Concern Color Code remained at Orange.

Seismic activity at Karymsky was above background levels during 13-20 July, with 500-900 shallow earthquakes occurring daily. Based on seismic interpretation, ash plumes may have risen to altitudes as high as 4.5 km (14,800 ft) a.s.l. Ash plumes drifted SE and SW and a thermal anomaly in the crater were visible on satellite imagery during 14-18 July. Plumes rose to estimated altitudes of 4.5 km (14,800 ft) a.s.l. based on atmospheric profiles. The Level of Concern Color Code remained at Orange

Based on satellite imagery, the Tokyo VAAC reported that an ash plume rose to an altitude of 5.2 (17,000 ft) a.s.l. on 20 July and drifted SW.

During 6-13 July, seismic activity at Karymsky was above background levels. Based on seismic interpretation, ash plumes may have risen to altitudes of 2.5 km and 3.8 km (8,200 ft and 12,500 ft) a.s.l. on 7 and 10 July, respectively. A thermal anomaly in the crater was visible on satellite imagery during 10-11 July. The Level of Concern Color Code remained at Orange.

Based on pilot reports, satellite imagery, observations in the Petropavlovsk-Kamchatsky Flight Information Region (FIR), and KEMSD, the Tokyo VAAC reported that an ash plume rose to an altitude of 9.1 (30,000 ft) a.s.l. on 11 July. Based on information from KEMSD, the Tokyo VAAC reported that an ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. on 16 July. Ash was not identified on satellite imagery.

During 29 June-6 July, seismic activity at Karymsky was above background levels. The seismic data indicated that ash plumes may have risen to altitudes of 2.7 and 4.6 km (8,900 and 15,100 ft) a.s.l. on 1 and 4 July, respectively. A thermal anomaly in the crater was visible on satellite imagery on 30 June and 1 July. The Level of Concern Color Code remained at Orange.

Based on information from KEMSD, the Tokyo VAAC reported that an eruption plume rose to an altitude of 2.4 km (8,000 ft) a.s.l. on 8 July. Ash was not identified on satellite imagery.

Seismic activity at Karymsky indicated that ash plumes possibly rose to an altitude of 6.8 km (22,300 ft) a.s.l. during 8-13 June. Seismicity was above background levels during 8-15 June. On 11 June, ash plumes were visible on satellite imagery drifting S and SW. A thermal anomaly was visible in the crater during 9-10 and 12-13 June. The Level of Concern Color Code remained at Orange

Based on information from KEMSD, the Tokyo VAAC reported that eruption plumes rose to 3-6.1 km (10,000-20,000 ft) a.s.l. during 13-14 and 17 June. Ash was not identified on satellite imagery.

Seismic activity at Karymsky was slightly above background levels during 1-8 June. According to visual observations, a gas-and-steam plume was visible on 5 June. KVERT lowered the Level of Concern Color Code from Orange to Yellow.

On 9 June, seismic data indicated that an explosion may have produced an ash plume that rose to an altitude of 3.8 km (12,500 ft) a.s.l. Strong seismicity and further possible explosions or avalanches followed the event. Clouds obscured summit observations. The Level of Concern Color Code was raised to Orange.

Based on information from KEMSD, the Tokyo VAAC reported that eruption plumes rose to 3.7-7 km (12,000-23,000 ft) a.s.l. during 9-12 June. Ash was not identified on satellite imagery.

Seismic activity at Karymsky was above background levels during 27 April-4 May. A thermal anomaly was visible on satellite imagery; ash plumes were absent. The Level of Concern Color Code remained at Orange.

Seismic activity at Karymsky was above background levels during 20-27 April. Based on seismic interpretation, satellite imagery, and visual observation, ash plumes rose to altitudes of 4-4.5 km (13,100-14,800 ft) a.s.l. on 21 April and drifted SE. The Level of Concern Color Code remained at Orange.

Seismic activity at Karymsky was above background levels during 13-20 April. Ash plumes from explosions occurred during 13-20 April and may have reached altitudes of 4 km (13,000 ft) a.s.l. during 15-16 April and drifted E. Based on visual observation, a gas-and-steam plume rose to an altitude of 2.5 km (8,200 ft) a.s.l. on 19 April and a possible new lava flow was seen on the SW flank. A thermal anomaly in the crater was detected on satellite imagery during 14-16 April. Based on pilot reports, satellite imagery, and observations in the Petropavlovsk-Kamchatsky Flight Information Region (FIR), the Tokyo VAAC reported that an ash plume rose to an altitude of 7.6 (25,000 ft) a.s.l. and drifted SE. The Level of Concern Color Code remained at Orange.

Seismic activity at Karymsky was above background levels during 10-13 April. Ash plumes from explosions may have reached altitudes of 4 km (13,000 ft) a.s.l. during the reporting period. The Level of Concern Color Code remained at Orange.

Seismic activity at Karymsky was above background levels during 4-10 April, with 100-250 shallow earthquakes occurring daily. Ash plumes may have reached altitudes of 4.5 km (14,800 ft) a.s.l. during the reporting period. Based on satellite imagery and information from the Petropavlovsk-Kamchatsky Flight Information Region (FIR), AVO, pilot reports, and KEMSD, the Tokyo VAAC reported that eruption plumes rose to altitudes of 3.4-7.6 km (11,000-25,000 ft) a.s.l. on 5, 9, and 10 April. Plumes drifted SE and E on 9 and 10 April, respectively. A thermal anomaly in the crater was detected on satellite imagery during 4-5 and 7-10 April. The Level of Concern Color Code remained at Orange.

Based on satellite imagery and information from the Petropavlovsk-Kamchatsky Flight Information Region (FIR), the Tokyo VAAC reported that an eruption plume from Karymsky rose to an altitude of 3 km (10,000 ft) a.s.l. on 31 March.

Seismic activity at Karymsky increased on 23 March. Ash plumes may have reached altitudes of 4.6 km (15,000 ft) a.s.l., although no visual observations were reported. Diffuse emissions were seen on satellite imagery.

Seismic activity at Karymsky was above background levels during 16-22 February, with 100-180 shallow earthquakes occurring daily. Ash plumes may have reached altitudes of 3.0 km (9,900 ft) a.s.l. during the reporting period. A thermal anomaly in the crater was detected on satellite imagery during 16-19 February. Based on satellite imagery and information from KEMSD, the Tokyo VAAC reported that eruption plumes rose to altitudes of 4.0-5.2 km (13,000-17,000 ft) a.s.l. on 22 and 27 February. The Level of Concern Color Code remained at Orange.

Seismic activity at Karymsky was above background levels during 9-16 February, with 50-200 shallow earthquakes occurring daily. Minor explosions may have occurred and a thermal anomaly in the crater was detected on satellite imagery. The Level of Concern Color Code remained at Orange.

Seismic activity at Karymsky was above background levels during 19-26 January, with 100-250 shallow earthquakes occurring daily. Ash plumes may have reached altitudes of 3.5 km (11,500 ft) a.s.l. during 7-8 January. A thermal anomaly in the crater was detected during the reporting period. The Level of Concern Color Code remained at Orange.

Activity at Karymsky continued during 5-12 January, with 100-350 shallow earthquakes occurring daily. Ash plumes may have reached altitudes of 2.5 km (8,200 ft) a.s.l. during 7-8 January. The Level of Concern Color Code remained at Orange.

Activity at Karymsky continued during 27 December-2 January, with 100-130 shallow earthquakes occurring daily. Ash plumes may have reached altitudes of 2 km (6,600 ft) a.s.l. A thermal anomaly in the crater was detected during 21-22 December. The Level of Concern Color Code remained at Orange.

Seismic data from Karymsky were not available during 15-22 December. Based on ground and pilot observations, ash plumes rose to 7 km (23,000 ft) a.s.l. and drifted E and a thermal anomaly in the crater was detected on satellite imagery during the reporting period. The Level of Concern Color Code remained at Orange.

Seismic data from Karymsky were not available during 8-15 December. Ash plumes were observed drifting in all directions during the reporting period. A thermal anomaly in the crater was detected on satellite imagery during 8-12 December. Pilots reported that an ash plume rose to an altitude of 7 km (23,000 ft) a.s.l. and drifted E on 17 December. Based on satellite data, the Tokyo VAAC reported that an ash plume rose to an altitude of 8.2 km (27,000 ft) a.s.l. and drifted E. The Level of Concern Color Code remained at Orange.

Seismic data from Karymsky was not available during 1-8 December. Pilots from international airlines reported that on 2 December ash plumes rose to 6.9 km (22,600 ft) a.s.l. and drifted E. Plumes also drifted E on 5-6 December. A thermal anomaly in the crater was detected on 3 and 6-7 December. Plumes were visible on satellite imagery on 9 December, extending as far as 15 km W. The Level of Concern Color Code remained at Orange.

Seismic data from Karymsky was unavailable during 29 November-5 December. A large thermal anomaly in the crater was detected on 26, 27, and 29 November. On 29 November ash plumes drifted NE. Based on pilot reports and satellite imagery, the Tokyo VAAC reported that during 1-2 December, ash plumes rose to 7 km (23,000 ft) a.s.l. and drifted N and E. The Level of Concern Color Code remained at Orange.

Seismic data from Karymsky was available during 18-19 November. Seismicity was elevated above background levels and the number of shallow earthquakes was more than 90 per day. Explosions produced ash plumes that possibly reached altitudes of 2.5 km (8,200 ft) a.s.l. based on seismic data. A thermal anomaly in the crater was detected on 18-19 and 21-23 November. The Level of Concern Color Code remained at Orange.

Seismic data from Karymsky was available during 10-11 November. Seismicity was elevated above background levels and the number of shallow earthquakes ranged 130-420 per day. Based on seismic data, explosions produced ash plumes that possibly reached altitudes of 2.5 km (8,200 ft) a.s.l. Plumes were visible on satellite imagery on 13 November and drifted W. The Level of Concern Color Code remained at Orange.

Seismic data from Karymsky were not available during 4-10 November, except on 2, 3, and 7 November, when seismicity was elevated above background levels. Explosions produced ash plumes that may have reached altitudes of 3 km (9,800 ft) a.s.l. Based on satellite imagery, plumes drifted NE on 2 November and SE during 6 and 7 November. A thermal anomaly in the crater was detected on 2-3 and 5-7 November. The Level of Concern Color Code remained at Orange.

Activity at Karymsky continued during 26-29 October, with 150-550 shallow earthquakes occurring daily. Based on interpretations of seismic data and satellite imagery, ash plumes may have reached altitudes of 2-4.8 km (6,600-15,700 ft) a.s.l. An ash cloud extended 70 km to the NE on 28 October. A thermal anomaly in the crater was detected on 27-28 and 30-31 October and 2 November. Karymsky remained at Concern Color Code Orange.

Seismic activity increased at Karymsky during 21-27 October, with 350-550 shallow earthquakes occurring daily. Explosions produced ash plumes that may have reached altitudes of 2.5-5.0 km (8,200-16,400 ft) a.s.l. and drifted E, NE, and SE. Staff from the Institute of Volcanology and Seismology (IVS) observed a series of ash bursts that produced plumes to 2.0 km (6,600 ft) a.s.l. on 25 October. A thermal anomaly in the crater was detected on satellite imagery during 19-24 October.

Seismic data and satellite observations reported by KVERT indicated that moderate ash eruptions from Karymsky continued during 14-20 October. Weak local shallow earthquakes occurred at a rate of 100-290 per day. Ash explosions that were thought to have risen to about 3.6 km (11,800 ft) a.s.l. drifted E on 17-19 October. A thermal anomaly from the volcanic crater was noted on 13, 15, and 17-19 October. Based on a pilot observation, the Tokyo VAAC reported that on 23 October an ash plume rose to 5.2 km (17,000 ft) a.s.l. and drifted E. The Level of Concern Color Code remained at Orange.

Activity at Karymsky continued during 11-17 October, with 100-190 shallow earthquakes occurring daily. Based on interpretations of seismic data and satellite observations, ash plumes may have reached altitudes of 2.5 km (8,200 ft) a.s.l. A thermal anomaly in the crater was detected on 7 and 12 October. According to the Tokyo VAAC, an ash plume rose to 3.7 km (12,000 ft) a.s.l. on 17 October. Karymsky remained at Concern Color Code Orange.

KVERT reported on 6 October that activity at Karymsky continued during 30 September-6 October, with 120-190 shallow earthquakes occurring daily. Explosions produced ash plumes that possibly reached altitudes of 2.5 km (8,200 ft) a.s.l. A thermal anomaly in the crater was detected on 30 September, and 2 and 4 October. Karymsky remained at Concern Color Code Orange.

Seismic data and satellite observations reported by KVERT indicated that moderate ash eruptions of Karymsky continued during 23-29 September. Weak local shallow earthquakes occurred at a rate of 100-250 per day. Ash explosions were thought to have risen to about 4.5 km (14,800 ft) a.s.l. on 22 September, and up to 2.5 km (8,200 ft) a.s.l. on the other days of that week. A thermal anomaly over the volcanic crater was noted on 23 and 26-27 September. The Level of Concern Color Code remained at Orange.

Seismic data and satellite observations reported by KVERT indicate that moderate ash eruptions were continuing from Karymsky during 16-22 September. There have been 40-200 weak shallow earthquakes recorded each day. A thermal anomaly over the crater was noted on 18-19 September. Based on visual observations, volcanologists in the area on 19 September estimated ash explosions to have reached altitudes of 2.3 km (7,500 ft) a.s.l. Ash plumes extending 16-40 km SW and SE were noted at satellite images on 18-19 September.

KVERT reported on 15 September that the Concern Color Code level at Karymsky was raised from Yellow to Orange. Approximately 50-100 shallow earthquakes occurred daily during 9-15 September. During 8-10 and 12 September, a thermal anomaly was detected in the crater. An ash plume was visible on satellite imagery extending ~140 km SE on 13 September. On 17 and 19 September, eruption plumes rose to altitudes of 2.7 km (9,000 ft) a.s.l. and drifted SE.

KVERT reported on 8 September that the Concern Color Code level at Karymsky was lowered from Orange to Yellow. Approximately 30-90 shallow earthquakes occurred daily. During 1-4 September, a thermal anomaly was detected in the crater.

Activity at Karymsky continued during 26 August-1 September, with 30-70 shallow earthquakes occurring daily. Based on interpretations of seismic data, ash plumes reached altitudes of 3 km (10,000 ft) a.s.l. A thermal anomaly in the crater was detected on 26 and 28 August. Karymsky remained at Concern Color Code Orange.

Based on interpretations of seismic and satellite data, KVERT reported that during 5-11 August explosions from Karymsky produced ash plumes that rose to altitudes of 3.5 km (11,500 ft) a.s.l. and extended NW. Approximately 100-250 shallow earthquakes occurred daily. A thermal anomaly was present in the crater during the reporting period. Karymsky remained at Concern Color Code Orange.

Based on interpretations of seismic and satellite data, KVERT reported that ash explosions from the summit crater of Karymsky continued during 26-28 July. On 24 July, volcanologists reported that an ash plume rose to an altitude of 6 km (19,700 ft) a.s.l. A large thermal anomaly over the crater was visible on satellite imagery. KVERT warned that activity from the volcano could affect nearby low-flying aircraft. Karymsky remained at Concern Color Code Orange.

Based on interpretations of seismic data from Karymsky during 15-21 July, KVERT reported that ash plumes reached altitudes of 6 km (19,700 ft) a.s.l. According to the Tokyo VAAC, the Kamchatkan Experimental and Methodical Seismological Department (KEMSD) reported that on 23 and 24 July ash plumes reached altitudes of 6.7 km (22,000 ft) a.s.l. Approximately 180-400 shallow earthquakes occurred daily during the reporting period. A thermal anomaly in the crater was observed during 15-20 July. Karymsky remained at Concern Color Code Orange.

Based on interpretations of seismic data from Karymsky during 1-7 July, ash plumes reached altitudes of 4 km (13,100 ft) a.s.l. According to the Tokyo VAAC, the Kamchatkan Experimental and Methodical Seismological Department (KEMSD) reported that on 10 July ash plumes reached altitudes of ~5.2 km (17,000 ft) a.s.l. Approximately 100-350 shallow earthquakes occurred daily during 29 June-3 July and increased to 1000 per day during 4-5 July. A thermal anomaly in the crater was observed on 30 June, 1 July, and 6 July. Karymsky remained at Concern Color Code Orange.

Activity at Karymsky continued during 23-30 June, with 100-350 shallow earthquakes occurring daily. Based on interpretations of seismic data, ash plumes reached altitudes of 3.5 km (11,500 ft) a.s.l. According to the Tokyo VAAC, the Kamchatkan Experimental and Methodical Seismological Department (KEMSD) reported that on 1 and 3 July ash plumes reached altitudes of 3.7 km (12,000 ft) a.s.l. A thermal anomaly in the crater was observed during 24-27 June. Karymsky remained at Concern Color Code Orange.

Activity at Karymsky continued during 21-27 June, with 200-700 shallow earthquakes occurring daily. Based on pilot reports, on 19 June ash plumes rose up to 4 km (13,100 ft) a.s.l. and traveled NE. A thermal anomaly in the crater was observed during 17,19, and 22 June. Karymsky remained at Concern Color Code Orange.

Activity at Karymsky continued during 10-16 June, with 400-600 shallow earthquakes occurring daily. Ash plumes up to 5 km (16,400 ft) a.s.l. traveling SE were observed by pilots. A large thermal anomaly over the crater was visible on satellite imagery. Karymsky remained at Concern Color Code Orange.

During 27 May to 2 June, ash explosions from the summit of Karymsky continued. A large thermal anomaly in the crater was observed during 27-31 May. KVERT warned that activity from the volcano could affect nearby low-flying aircraft. Karymsky remained at Concern Color Code Orange.

Based on interpretations of seismic and satellite data, KVERT reported that ash explosions from the summit crater of Karymsky continued during 20-26 May. On 27 May, the Tokyo VAAC reported an ash plume an elevation of 3.7 km (12,000 ft) a.s.l. KVERT warned that activity from the volcano could affect nearby low-flying aircraft.

During 12-19 May, eruptive activity continued at Karymsky. Based on interpretations of seismic and satellite data, ash plumes rose to a height of 8 km (26,200 ft) a.s.l. Ash plumes extended for about 50 km to the S and NE. KVERT warned that activity from the volcano could affect nearby low-flying aircraft. Karymsky remained at Concern Color Code Orange.

During 5-12 May, eruptive activity continued at Karymsky. Based on interpretations of seismic data, ash plumes rose to a height of ~5.3 km (17,400 ft) a.s.l. A thermal anomaly was present on satellite data when the crater was visible. Ash plumes drifted SE. KVERT warned that activity from the volcano could affect nearby low-flying aircraft. Karymsky remained at Concern Color Code Orange.

Intermittent eruptive activity continued at Karymsky during 21-28 April. Based on interpretations of seismic data, ash plumes rose to a height of ~3.8 km (12,500 ft) a.s.l. during the report week. Satellite imagery showed a large thermal anomaly at the volcano's crater, and numerous ash plumes and deposits extending 10-200 km SE and E of the volcano. Karymsky remained at Concern Color Code Orange.

Strombolian-to-Vulcanian activity continued at Karymsky during 7-14 April. Satellite imagery showed ash plumes extending ~40-145 km E and SE of the volcano, and a large thermal anomaly at the volcano's crater. Karymsky remained at Concern Color Code Orange.

During 17-24 March, Strombolian activity continued at Karymsky. Several ash plumes were visible on satellite imagery at a height of ~4 km (13,100 ft) a.s.l. and extended SE and E. A thermal anomaly was seen at the volcano during periods of visibility. About 40-450 small earthquakes occurred daily. Karymsky remained at Concern Color Code Orange.

Strombolian activity continued at Karymsky during 3-10 March. A thermal anomaly over the volcanic crater was visible on satellite imagery during the entire week. Numerous ash plumes extending up to 150 km SE and E of the volcano were also visible on satellite imagery. On 9 March, a pilot reported an ash plume at a height of ~3 km (9,850 ft) a.s.l. Karymsky remained at Concern Color Code Orange.

During 24 February to 3 March, Strombolian activity continued at Karymsky. A large thermal anomaly was visible at the volcano's crater during the entire week. Numerous ash plumes were visible on satellite imagery, extending as far as 140 km NE and E. Karymsky remained at Concern Color Code Orange.

During 17-24 February, Strombolian activity continued at Karymsky. Satellite imagery showed a large thermal anomaly at the volcano's crater and numerous ash plumes extending as far as 117 km. Karymsky remained at Concern Color Code Orange.

According to reports from pilots of local airlines, ash emissions from Karymsky rose to 4-5 km (13,100-16,400 ft) a.s.l. during 30-31 January. The ash plumes extended 13-29 km from the volcano to the SW and SE, respectively. A thermal anomaly was visible at the lava dome during 27 January to 3 February, except when the volcano was obscured by clouds on the 28th. KVERT warned that activity from the volcano could affect nearby low-flying aircraft. Karymsky remained at Concern Color Code Orange.

Seismic activity indicated that ash explosions from the summit crater of Karymsky continued during 14-20 January 2006. Ash plumes extending 6-9 km S from the volcano were registered on 12 January. A thermal anomaly over the dome was noted during 13-15 January. According to seismic data on 14-15 January, two possible ash plumes rose up to 3.0-3.4 km (9,800-11,200 feet) a.s.l. Karymsky remained at Concern Color Code Orange.

KVERT reported on 30 December that a new 60- to 80-m diameter cone formed at Karymsky's summit. A small lava dome that was 20-30 m in diameter was noted in the crater of the cone. During 23-30 December, many weak, shallow earthquakes were recorded at the volcano. Interpretations of seismic data suggested that seven ash plumes rose 2.5-4 km (8,200-13,100 ft) a.s.l. during 24 and 26-27 December. Ash plumes extended mainly E, SE, and occasionally SW of the volcano. KVERT reported that ash emissions could affect low-flying aircraft in the vicinity of the volcano. Karymsky remained at Concern Color Code Orange.

Seismicity at Karymsky during 9-16 December indicated that growth of the lava dome in the summit crater continued. Ash plumes were visible on satellite imagery on 9 and 10 December. Karymsky remained at Concern Color Code Orange.

Seismicity at Karymsky remained above background levels during 1-2 December, and there were no seismic data during 3-9 December. Ash clouds were visible on satellite imagery extending SE on 6 and 7 December. Karymsky remained at Concern Color Code Orange.

The lava dome in Karymsky's crater continued to grow during 11-18 November. No seismic data were available after 10 November. A thermal anomaly was visible at the volcano on 15 and 17 November. Karymsky remained at Concern Color Code Orange.

Seismicity was above background levels at Karymsky during 4-11 November, when five gas-and-steam plumes with some ash may have reached heights of 3-3.5 km (9,850-11,500 ft) a.s.l. The lava dome inside the volcano's crater continued to grow. Karymsky remained at Concern Color Code Orange.

Seismicity was above background levels at Karymsky during 28 October to 4 November. Based on interpretations of seismic data, three gas plumes containing some ash possibly rose 3-3.8 km (9,850-12,500 ft) a.s.l. during 29-31 October and 1 November. Ash plumes were visible on satellite imagery extending NE on 31 October and 2 November. Karymsky remained at Concern Color Code Orange.

During 21-28 October, seismicity at Karymsky was above background levels. Based on interpretations of seismic data, five ash-and-gas plumes may have reached heights of 2.5-3.5 km (8,200-11,500 ft) a.s.l. on several days. A thermal anomaly at the volcano was visible on satellite imagery. Karymsky remained at Concern Color Code Orange.

Seismicity at Karymsky was above background levels during 14-21 October. Visual observations on 17 October revealed that the lava dome in the volcano's crater had been partially destroyed. Based on interpretations of seismic data, three ash-and-gas plumes may have risen 2.5-4 km (8,200-13,100 ft) a.s.l. during 14-16 October. Karymsky remained at Concern Color Code Orange.

Seismic signals associated with possible small ash-and-gas plumes from Karymsky were recorded during 9-16 September. A thermal anomaly was visible at the volcano on satellite imagery on 15 September. Karymsky remained at Concern Color Code Orange.

Seismicity was above background levels at Karymsky during 2-9 September. Based on interpretations of seismic data, small ash-and-gas plumes occurred during the report week. An ash-and-steam plume was faintly visible on satellite imagery extending ESE. Karymsky remained at Concern Color Code Orange.

Seismicity was above background levels at Karymsky during 26 August to 2 September. Interpretations of seismic data suggested that ash-and-gas plumes may have risen to 4.5 km (14,800 ft) a.s.l. An ash plume was visible at a height of ~5.8 km (19,000 ft) a.s.l. on 27 August. Karymsky remained at Concern Color Code Orange.

Seismicity was above background levels at Karymsky during 22-29 July. Based on interpretations of seismic data, ash-and-gas plumes may have reached heights of 2.5-3 km (8,200-9,800 ft) a.s.l. On 22 July, a weak thermal anomaly and a short E-drifting ash-and-gas plume were visible on satellite imagery. Karymsky remained at Concern Color Code Orange.

Seismicity was above background levels at Karymsky during 1-8 July. Based on interpretations of seismic data during 4-7 July, ash-and-gas plumes may have risen to ~3 km above the crater (14,900 ft a.s.l.). Karymsky remained at Concern Color Code Orange.

Due to a decrease in seismic and volcanic activity during 3-10 June, KVERT decreased the Concern Color Code at Karymsky from Orange to Yellow. During the report week, seismicity decreased to slightly above background levels, and 25-80 shallow earthquakes occurred daily. A weak gas-and-steam plume was observed on 4 June.

Seismicity decreased at Karymsky during 27 May to 3 June, but remained above background levels. No information was available about ash-and-gas explosions. Karymsky remained at Concern Color Code Orange.

During 13-20 May, seismic activity and the height of ash explosions increased at Karymsky in comparison to the previous week. Ash-and-gas plumes rose to ~3.5 km above the crater (16,500 ft a.s.l.) and fresh ash deposits were present on the W and E sectors of the volcano. A thermal anomaly continued to be visible on satellite imagery. Karymsky remained at Concern Color Code Orange.

High seismic activity at Karymsky continued during 6-13 May. The number of local shallow events was 150-500 per day during the week. According to seismic data, possible ash-and-gas plumes rose up to the 1,000 m above the crater on 5, 8, and 9 May. According to satellite data, a thermal anomaly was registered on 6 and 8 May. Gas-and-steam plumes containing some ash extended ~40 km E on 6 May and ~30 km S on 9 May. Clouds obscured the volcano at other times. A larger eruption to 3 km altitude (10,000 feet) was reported on 18 May. Karymsky remained at Concern Color Code Orange.

High seismicity continued through the week ending on 5 May. Ash-and-gas explosions during 2-3 May rose a short distance above the crater. Ash deposits extending SW were observed on 3 May. A thermal anomaly was also detected by satellite instruments during this period, as seismic data suggested many possible plumes rising as high as 1 km above the crater. Karymsky remained at Concern Color Code Orange.

Seismicity at Karymsky was above background levels during 22-29 April, with 300-650 shallow earthquakes occurring daily. Possible ash-and-gas explosions rose to a height of ~1 km above the volcano's crater (~8,300 a.s.l.). The evenings of 26 and 27 April, Strombolian activity was seen in two of the volcano's crater. Volcanic bombs rose to ~300 m above the craters. Ash-and-gas explosions rose to ~1 km above the crater (~8,300 ft a.s.l.). Ash fell to the SE on 22-23 April. Pyroclastic-flow deposits were seen on the NNW flank of the volcano. Karymsky remained at Concern Color Code Orange.

Seismic activity was above background levels at Karymsky during 8-15 April, with the number of shallow earthquakes increasing from 100 to 1,500 per day during the week. Possible ash-and-gas explosions may have reached 1 km above the crater (8,300 ft a.s.l.) during 12-13 April. Ash-and-gas plumes extended ~30 km on 8 and 9 April. Ash deposits extended ~10 km on the S side of the volcano. Karymsky remained at Concern Color Code Orange.

During 1-8 April, seismicity was above background levels at Karymsky, with the number of shallow daily earthquakes decreasing from 500 to 100 during the week. Ash deposits extended ~15 km SW on 2 April. Karymsky remained at Concern Color Code Orange.

On 28 December, an observed eruption at Karymsky produced a plume composed primarily of gas and steam, but with some ash, that rose to ~1 km above the crater. Thermal anomalies were also visible on satellite imagery on 27 and 28 December. On 30 December the Tokyo VAAC reported that a plume was present up to ~8 km a.s.l. and extending SW. Karymsky remained at Concern Color Code Orange.

Seismic activity was above background levels during 11-17 September. The number of local shallow events was 140-220 events per day. According to seismic data, several possible ash-and-gas explosions up to 2 km a.s.l. occurred on 10-11 September, and up to 2.5-6 km on 12-14 September. Karymsky remained at Concern Color Orange.

During 3-10 September, seismicity was above background levels at Karymsky. The number of shallow events increased from 55 to 250 during 3-6 September. Based on interpretations of seismic data, several plumes from ash-and-gas explosions may have risen 4.5-5.5 km a.s.l. A pilot observed an ash plume at a height of ~ 4 km a.s.l. on 5 September. Karymsky remained at Concern Color Orange.

Seismicity was slightly to moderately above background levels at Karymsky during 27 August to 3 September. During 26-29 August, there were 140-180 shallow earthquakes recorded daily. Based on interpretations of seismic data, several ash-and-gas plumes may have risen to ~5.5 km a.s.l. on 31 August and 1 September. Karymsky remained at Concern Color Orange.

An increase in volcanic activity led KVERT to raise the Concern Color Code at Karymsky from Yellow to Orange on 1 September. The level of seismicity was above background levels during 31 August to 1 September, with 130 shallow earthquakes occurring. Based on interpretations of seismic data, possible ash plumes rose to 5.5 km a.s.l. on 31 August and 1 September.

During 30 July to 6 August seismicity at Karymsky was slightly above background levels, with 110-180 shallow earthquakes recorded during the week. KVERT reduced the Concern Color Code to Yellow from Orange.

During 9-16 July seismicity at Karymsky was above background levels, with 260-470 shallow earthquakes recorded during the week. On 14 July an explosion produced an ash-and-gas plume to a height of ~7.5 km a.s.l. Karymsky remained at Concern Color Code Orange.

Seismicity at Karymsky was above background levels during 24-28 June, with 300-400 shallow earthquakes occurring. During 29-30 June, the number of earthquakes increased to 600-950. Based on interpretations of seismic data, daily ash-and-gas explosions may have risen to 2.5-4.5 a.s.l. On 28 June ash-and-gas plumes rose to 2.5-3 km every 7-10 minutes. Karymsky remained at Concern Color Code Orange.

Between 28 May and 4 June, seismic activity was above background levels at Karymsky with up to 520 shallow earthquakes recorded and possible gas-and-ash plumes up to 4.5 km a.s.l. each day. A possible small eruption was observed on 28 May and an eruption was also observed on 2 June. An eruption on 6 June produced a plume that rose to ~3 km a.s.l. and extended to the SE. Karymsky remained at Concern Color Code Orange.

During 7-14 May, seismicity was above background levels at Karymsky, with 330-450 shallow earthquakes occurring daily. Based on interpretations of seismic data, possible ash-and-gas explosions rose to 2.5-3 km a.s.l. daily. On 8 May an ash plume was visible extending more than 16 km NE of the volcano. Karymsky remained at Concern Color Code Orange.

Seismicity was above background levels at Karymsky during 16-23 April, with 240-450 shallow earthquakes occurring per day. Based on interpretations of seismic data, ash-and-gas explosions may have produced plumes to 2.5-3.5 km a.s.l. daily. On 17 and 20 April, ash deposits were seen NW, SW, and E of the volcano. On 19 April, an ash plume was seen on satellite imagery extending 47 km S. Karymsky remained at Concern Color Code Orange.

During 9-16 April, seismicity at Karymsky remained above background with 300-470 earthquakes per day and daily eruptions produced plumes to ~3.5 km a.s.l. During 12-19 April up to 400 small explosions per day produced plumes that rose ~0.5-1.5 km above the vent. According to the Tokyo VAAC, an eruption on 18 April produced a gas-and-ash plume that rose to ~4.6 km a.s.l. and extended SE. Karymsky remains at Concern Color Code Orange.

During 2-9 April seismicity was above background levels at Karymsky, with 270-400 shallow earthquakes occurring daily. Based on interpretations of seismic data, daily ash-and-gas explosions may have produced plumes to heights of 2.5-3 km a.s.l. During 6-7 April, ash plumes extended 15-40 km to the NE and N. On 7 April, ash deposits were noted on the volcano to the NNE, SSW, E, and W. Karymsky remained at Concern Color Code Orange.

Seismicity remained above background levels at Karymsky during 26 March to 2 April, with 240-380 shallow earthquakes occurring per day. Based on interpretations of seismic data, plumes from ash-and-gas explosions may have reached 3.5 km a.s.l. every day. On 30 March ash deposits were seen extending SE and SW from the volcano. Karymsky remained at Concern Color Code Orange.

During 19-26 March seismicity was above background levels at Karymsky with 250-300 shallow earthquakes per day. Based on interpretations of seismic data, daily explosions may have produced ash-and-gas plumes to a height of ~3.5 km a.s.l. Karymsky remained at Concern Color Code Orange.

Seismicity was above background levels at Karymsky during 12-19 March, with 250-350 shallow earthquakes occurring per day. Based on interpretations of seismic data, daily ash-and-gas explosions may have produced plumes to a height of ~3 km a.s.l. Karymsky remained at Concern Color Code Orange.

Seismicity at Karymsky was at background levels during 26-28 February, and above background levels during 28 February to 5 March. During the week, there were 30-400 shallow earthquakes recorded. Based on interpretations of seismic data, ash-and-gas explosions produced plumes to 3-3.5 km a.s.l. on 29 February and during 1-3 March. Karymsky remained at Concern Color Code Orange.

Seismicity remained above background levels at Karymsky during 20-27 February, with 30-100 shallow earthquakes during the week. Based on interpretations of seismic data, several ash explosions during 19-25 may have produced ash plumes to a maximum height of 6.5 km a.s.l. On 20 February an ash plume was seen rising to ~3.5 km a.s.l. Satellite imagery on 20 February showed ash deposits as far away as 35 km S of the volcano. Karymsky remained at Concern Color Code Orange.

During 12-16 February, seismicity was above background levels at Karymsky. No seismic data were recorded during 17-18 February. Based on interpretations of seismic data, during 12-14 February five ash-and-gas explosions produced plumes that rose 4-4.5 km a.s.l., and on 15 February explosions produced two plumes to ~3 km a.s.l. Karymsky remained at Concern Color Code Orange.

Seismicity was above background levels at Karymsky during 6-13 February, with 30-190 shallow earthquakes occurring per day. Based on interpretations of seismic data, four possible ash-and-gas explosions produced plumes to ~6.5 km a.s.l. on 10 February. According to data from the Airport Meteorological Center in Yelizovo, on 9 and 12 February pilots saw ash plumes that rose to ~5.5 km a.s.l. Karymsky remained at Concern Color Code Orange.

Seismicity was above background levels at Karymsky during 30 January to 6 February, with 160-220 shallow earthquakes occurring per day. Based on interpretations of seismic data, during 30-31 January possible ash-and-gas explosions produced plumes that rose 2.5-3 km a.s.l. Karymsky remained at Concern Color Code Orange.

Seismicity was above background levels at Karymsky during 9-16 January, with 150-300 earthquakes recorded. Ash-and-gas plumes may have risen 1.5-3 km above the volcano. According to the Airport Meteorological Center (AMC) in Yelizovo, during the report period a pilot saw an ash plume rise ~5.5 km above the volcano and extend SSW. On 12 January staff of the Kamchatkan Experimental & Methodical Seismological Department (KEMSD) saw an ash plume rise ~2 km above the volcano and explosions that occured every 5-7 minutes. On 10 January ash deposits were seen on the volcano's snow-covered flanks extending SE. Karymsky remained at Concern Color Code Orange.

Seismicity was above background levels at Karymsky during 1-5 January, with 40-150 shallow earthquakes occurring per day. The seismic station was not working during 5-9 January. During 2-4 January, ash deposits were visible on the volcano's snow-covered flanks extending ESE, NNW, and NNE. The Tokyo VAAC reported that ash was visible on satellite imagery on 8 January at a height of ~7 km a.s.l. drifting SSW. Karymsky remained at Concern Color Code Orange.

Seismicity was above background levels at Karymsky during 26 December to 2 January, with 200-270 shallow earthquakes recorded per day. Possible ash-and-gas plumes rose 2-3.5 km above the volcano. On 25, 29, and 31 December explosions with accompanying pyroclastic flows may have been recorded. Karymsky remained at Concern Color Code Orange.

On 23 December at 0359 and on 24 December at 1605 KVERT recorded possible explosions at Karymsky that were accompanied by pyroclastic flows. During 19-26 December, seismicity at Karymsky was above background levels, with 40-200 earthquakes occurring per day. In addition, possible gas-and-ash explosions rose 1-2 km above the volcano. The number of earthquakes decreased during 18-20 December, then increased during 21-24 December. Karymsky remained at Concern Color Code Orange.

During 7-14 November, seismicity was above background levels at Karymsky. The number of shallow earthquakes increased from 150 to 220 per day. Possible ash-and-gas explosions rose to 1-1.5 km above the volcano. Karymsky remained at Concern Color Code Orange.

During 3-10 October, seismicity at Karymsky was above background levels. Seismic data indicated that on 4 October at 1848 an ash explosion produced a cloud to a height of 4.5 km above the crater. The number of shallow earthquakes increased from ~150 on 4 October to ~350 per day during 5-8 October. Ash plumes extending 60 km SE and 30 km NE were observed on 4 and 7 October, respectively. The Concern Color Code at Karymsky was reduced from Orange to Yellow.

During 26 September to 3 October, seismicity was above background levels at Karymsky and the Concern Color Code was raised from Yellow to Orange. During 25-29 September, 200-270 shallow earthquakes occurred that indicated possible ash-and-gas explosions to heights of 1-1.5 km above the volcano. Interpretations of seismic data suggested that on 2 October at 0633 an ash explosion began that produced a plume to 3.5 km above the volcano. A seismic pause was recorded on 2 October.

Seismicity was above background levels at Karymsky during 12-19 September, with 210-300 shallow earthquakes occurring per day. These data indicated that possible ash-and-gas explosions occurred and rose 1-1.5 km above the crater. On 14 September an ash-and-gas plume rose 0.5 km above the crater. On 23 September, after 2 days of low seismicity, an explosion occurred at 1808 that produced an ash plume to 5 km a.s.l. Karymsky remained at Concern Color Code Yellow.

Seismic activity at Karymsky was above background levels during 29 August to 5 September. On 28 and 29 August ~120 shallow earthquakes occurred per day, and ash explosions rose to ~4.7 km a.s.l. The number of shallow earthquakes increased to 180 on 1 September, and then to 230 on 2-3 September. Seismic data indicated that ash-and-gas explosions reached 4.5 km a.s.l. On 30 August spasmodic tremor and a thermal anomaly visible on satellite imagery indicated the formation of a pyroclastic flow. The Concern Color Code at Karymsky was reduced from Orange to Yellow.

Due to increased volcanic activity at Karymsky, KVERT raised the Concern Color Code to Orange from Yellow on 29 August. On 29 August at 1240 and 1612 explosions occurred that produced ash plumes to heights of 4-4.7 km a.s.l. The plumes drifted E. During 22-29 August, seismicity was above background levels, with about 180 shallow earthquakes per day. These earthquakes indicated possible ash-and-gas explosions to heights of 1-1.5 km above the volcano.

Intermittent explosions occurred at Karymsky during 16-23 May. Seismicity was above background levels, with 150 to 320 shallow events occurring per day during 18-21 May. Seismic data indicated that ash-and-gas explosions reached heights up to 1 km above the crater, and gas blowouts and hot avalanches possibly occurred. On 18 May ash deposits were seen on snow on the volcano's S and SE flanks. Karymsky remained at Concern Color Code Yellow.

KVERT reported that Karymsky's seismicity was above background during the week ending 25 April, an interval when instruments registered ~40-100 volcanic earthquakes per day. The character of the seismicity suggested ash-and-gas explosions up to 1,000 m above the volcano's crater. According to Russian satellite data, ash deposits were detected ~35 km away in various directions from the volcano; these were noted the previous week, on 19-22 April, but not previously reported here. According to other observers on 21 April, an ash-and-gas plume rose 1,500 m above the volcano's crater. The level of concern color code stood at Yellow.

Karymsky's eruptive vigor increased. Although seismicity stood at background levels during the past week and slightly above background levels on 14 April, ten=s of volcanic earthquakes per day began to be registered. Observations made on 16 April suggested the presence of fresh ash deposits extending to the ESE for a distance of over 10 km from the summit. Some data suggested that on 17 April an ash-and-gas plume rose 1,000 m above the crater (to ~2,500 m a.s.l.). These events caused authorities to raise the hazard status from Green to Yellow. A 23 April aviation notice described an apparent ash plume at ~3 km a.s.l. directed S.

Seismicity was at background levels at Karymsky during 28 March to 4 April, so KVERT decreased the Concern Color Code from Yellow to Green. Fresh ash deposits were visible on satellite data during 17-18 March and a gas-and-steam plume was visible on 28 March.

An increase in seismicity and volcanism at Karymsky during 14-21 March led KVERT to raise the Concern Color Code from Green to Yellow. Seismicity was slightly above background levels on 19 March, with weak volcanic earthquakes occurring and other seismic data that day suggesting the presence of hot avalanches. During 17-20 March, ash deposits were visible on satellite images extending more than 30 km SW of the volcano.

Seismicity at Karymsky was at background levels during 20-23 February, so KVERT reduced the Concern Color Code on 28 February from Yellow to Green. Only an occasional very weak thermal anomaly was recorded on satellite imagery from late January to February. According to KVERT, the 7-year-period of eruptive activity at Karymsky may have come to an end.

Seismicity remained above background levels at Karymsky during 13-20 December, with about 190-210 shallow events recorded per day. The character of seismicity indicated that ash-and-gas explosions reached heights of ~1 km above the volcano, and vigorous, 5- to 10-minute-long gas emissions possibly occurred. Karymsky remained at Concern Color Code Yellow.

Seismicity remained above background levels at Karymsky during 6-13 December, with about 210-230 shallow events recorded per day. The character of seismicity indicated that ash-and-gas explosions reached heights of ~1 km above the volcano, and vigorous, 5- to 10-minute-long gas emissions possibly occurred. Karymsky remained at Concern Color Code Yellow.

Seismicity remained above background levels at Karymsky during 29 November to 6 December, with 200-300 shallow events recorded per day. The character of seismicity indicated that ash-and-gas explosions reached heights of ~1 km above the volcano, and 5- to 10-minute-long vigorous gas emissions possibly occurred. On 1 December an ash plume was seen rising ~500 m above the volcano, and the top of the volcano and its SE flank was covered with recent ashfall and debris from continuing Vulcanian/Strombolian eruptions. Karymsky remained at Concern Color Code Yellow.

Seismicity remained above background levels at Karymsky during 15-22 November, with 200-220 local shallow events recorded per day. The character of the seismicity indicated that ash-and-gas explosions rose to 1-2 km above the volcano and vigorous gas emissions lasting 5-10 minutes possibly occurred. On 20 November at 1157 a 20-minute-long seismic event was taken to indicate the possible occurrence of ash explosions up to 1 km above the crater and hot avalanches. Thermal anomalies (1-3 pixels) were visible on satellite imagery on several days. Karymsky remained at Concern Color Code Yellow.

Seismicity remained above background levels at Karymsky during 8-15 November, with approximately 250 local shallow events recorded per day. The character of the seismicity indicated that ash-and-gas explosions rose to 1-2 km above the volcano and vigorous gas emissions lasting 5-10 minutes possibly occurred. Thermal anomalies (1-2 pixels) were visible on satellite imagery several days. Karymsky remained at Concern Color Code Yellow.

Seismicity remained above background levels at Karymsky during 25 October to 1 November, with ~250 shallow earthquakes occurring per day. The character of the seismicity indicated that ash-and-gas explosions reached heights of 1 km above the volcano and vigorous 5- to 10-minute-long gas emissions possibly occurred. Thermal anomalies were visible on satellite imagery during 26-28 and 30 October. On the 31st at 1350 a pilot reported seeing an ash plume at a height of ~4 km a.s.l. extending SE. Seismic data from the Kamchatkan Experimental and Methodical Seismological Department revealed that the character of seismicity changed after 1400 that day. The data indicated that a lava flow probably traveled down the volcano's slope. A bright, large thermal anomaly was visible at the volcano on satellite imagery at 1314, as well as a ~60-km-long plume extending to the WSW. Pilots saw plumes on 1 November at 1100 rising to 4 km a.s.l. and drifting to the SE, and on 2 November at 0920 rising to 5.2 km a.s.l. Karymsky remained at Concern Color Code Yellow.

Seismicity remained above background levels at Karymsky during 18-25 October, with ~250 shallow earthquakes occurring per day. The character of the seismicity indicated that ash-and-gas explosions reached heights of 1 km above the volcano and vigorous 5- to 10-minute-long gas emissions possibly occurred. KVERT reported that a lava flow was probably traveling down the volcano's slopes. Thermal anomalies were visible on satellite imagery on several days, but ash was not. Karymsky remained at Concern Color Code Yellow.

During 13-20 September, seismicity at Karymsky remained above background levels, with 200-300 local shallow events occurring per day. The character of the seismicity indicated that ash-and-gas explosions rose to ~1 km above the volcano and gas blow-outs possibly occurred. On 16 September at 1217 a short-lived explosion sent an ash-and-gas plume to a height of ~3 km a.s.l. A thermal anomaly was visible on satellite imagery, but ash was not. Karymsky remained at Concern Color Code Yellow.

During 6-13 September, seismicity at Karymsky remained above background levels, with 200-250 local shallow events occurring per day. The character of the seismicity indicated that ash-and-gas explosions rose to ~1 km above the volcano and gas blow-outs possibly occurred. Observations of Karymsky on 8 September revealed three new small lava flows on the volcano's S and SE slopes. A thermal anomaly was visible on satellite imagery, but ash was not. Karymsky remained at Concern Color Code Yellow.

During 30 August to 6 September, activity at Karymsky was similar to activity throughout August. Seismicity remained above background, with 200-300 local shallow earthquakes occurring per day (150-250 occurred per day in August). The character of the seismicity indicated that ash-and-gas explosions rose to ~1 km above Karymsky and gas blow-outs possibly occurred. Thermal anomalies were visible on satellite imagery, but ash was not. Karymsky remained at Concern Color Code Yellow.

During 27 July-2 August, seismicity remained above background levels at Karymsky. Local, shallow seismic events decreased from 250 to 150 events per day. The character of the seismicity indicated that weak ash-and-gas explosions and gas blow-outs possibly occurred. The duration and intensity of blow-outs increased. A 2-pixel-large thermal anomaly was visible on satellite imagery on 26 July. Karymsky remained at Concern Color Code Yellow ("volcano is restless").

During 20-26 July, seismicity was above background levels at Karymsky. Local, shallow seismic events occurred at a rate of ~10 events per hour. The character of the seismicity indicated that weak ash-and-gas explosions and gas blow-outs possibly occurred. Satellite imagery on 25 July indicated a possible small ash plume moving to the SW. Karymsky remained at Concern Color Code Yellow ("volcano is restless").

During 12-19 July, seismicity was above background levels at Karymsky. During most of the report week ~10 local shallow seismic events occurred per hour, but by the end of the week the rate had slightly decreased. The character of seismicity suggested that weak ash-and-gas explosions and gas blow-outs had probably occurred. Karymsky remained at Concern Color Code Yellow ("volcano is restless").

Activity at Karymsky during 5-12 July was similar to activity during the past several months. Seismicity was above background levels at Karymsky, with ~10 earthquakes per hour. The character of seismicity suggested that weak ash-and-gas explosions and gas blow-outs had probably occurred. On the 9th a flight crew observed a volcanic plume that rose to a height of ~3 km a.s.l. Thermal anomalies were visible on satellite imagery, but ash was not. Karymsky remained at Concern Color Code Yellow ("volcano is restless").

During 28 June to 5 July, seismicity was above background levels at Karymsky, with ~10 earthquakes per hour. The character of seismicity suggested that weak ash-and-gas explosions and gas blow-outs had probably occurred. On 29 June at 1631 interpretations of seismic data indicated a possible ash-and-gas explosion that rose to a height of ~4 km a.s.l. Thermal anomalies were visible on satellite imagery, but ash was not. Karymsky remained at Concern Color Code Yellow ("volcano is restless").

During 21-28 June, seismicity was above background levels at Karymsky, with ~10 earthquakes occurring per hour. The character of seismicity suggested that weak ash-and-gas explosions and gas blow-outs had probably occurred. A steam-and-gas plume was visible on AVHRR satellite imagery on 25 June. Thermal anomalies were visible on satellite imagery, but ash was not. Karymsky remained at Concern Color Code Yellow ("volcano is restless").

During 14-21 June, seismicity was above background levels at Karymsky, with ~10 earthquakes occurring per hour. The character of seismicity suggested that weak ash-and-gas explosions and gas blow-outs had probably occurred. Thermal anomalies were visible on satellite imagery, but ash was not. Karymsky remained at Concern Color Code Yellow ("volcano is restless").

During 7-14 June, seismicity was above background levels at Karymsky, with ~10 earthquakes occurring per hour. The character of seismicity suggested that weak ash-and-gas explosions and gas blow-outs had probably occurred. Thermal anomalies were visible on satellite imagery, but ash was not. Karymsky remained at Concern Color Code Yellow ("volcano is restless").

During 31 May-7 June, seismicity was above background levels at Karymsky, with ~10 earthquakes occurring per hour. The character of seismicity suggested that weak ash-and-gas explosions and gas blow-outs had probably occurred. Thermal anomalies were visible on satellite imagery, but ash was not. Karymsky remained at Concern Color Code Yellow ("volcano is restless").

During 24-31 May, seismicity was above background levels at Karymsky, with ~10 earthquakes occurring per hour. The character of seismicity suggested that weak ash-and-gas explosions and gas blow-outs had probably occurred. Thermal anomalies were visible on satellite imagery, but ash was not. Karymsky remained at Concern Color Code Yellow ("volcano is restless").

During 17-24 May, seismicity was above background levels at Karymsky, with ~10 earthquakes occurring per hour. The character of seismicity suggested that weak ash-and-gas explosions, gas blow-outs, and debris avalanches occurred. Thermal anomalies were visible on satellite imagery, but ash was not. Karymsky remained at Concern Color Code Yellow ("volcano is restless").

During 10-17 May seismicity was above background levels at Karymsky and the rate of earthquakes slightly increased in the middle of the report week. The character of seismicity suggested that weak ash-and-gas explosions, gas blow-outs, and debris avalanches occurred. Observations from a helicopter on 10 May revealed that a new ~100-m-high cone had grown inside the crater and a lava flow was seen on the volcano's SSE slope. Thermal anomalies and an ash-and-steam plume were visible on satellite imagery. Karymsky remained at Concern Color Code Yellow ("volcano is restless").

During 3-10 May, Karymsky's seismicity remained above background levels and its character suggested that weak ash-and-gas explosions, gas blow-outs, and debris avalanches occurred. By the end of the week seismicity had slightly decreased. Thermal anomalies were visible on satellite imagery. On 9 May a faint ash-and-gas plume was also visible on satellite imagery extending 20 km to the SE. Karymsky remained at Concern Color Code Yellow ("volcano is restless").

During 27 April-3 May, Karymsky's seismicity remained above background levels and its character suggested that weak ash-and-gas explosions, gas blow-outs, and debris avalanches occurred. On 28 April at about 1630 an ash explosion produced a cloud to 500 m a.s.l. and deposited ash predominately to the W and to a lesser extent to the E. A new cone was visible inside the crater. Thermal anomalies were visible on AVHRR satellite imagery, but ash was not. The volcano remained at Concern Color Code Yellow ("volcano is restless").

During 19-26 April, Karymsky's seismicity was above background levels and its character suggested that weak ash-and-gas explosions, gas blow-outs, and debris avalanches occurred. Thermal anomalies were visible on AVHRR satellite imagery. Traces of ashfall were visible on MODIS imagery on 17 April. The volcano remained at Concern Color Code Yellow ("volcano is restless").

A pilot reported observing an ash cloud from an explosion at Karymsky on 15 April at 1115 that rose 3 km above the volcano. During 12-19 April, seismicity was above background levels and its character indicated that weak ash-and-gas explosions, gas blow-outs, and debris avalanches possibly occurred. Thermal anomalies were visible on AVHRR satellite imagery. The volcano remained at Concern Color Code Yellow ("volcano is restless").

After about 6 days of instrument downtime, the seismic station near Karymsky began to operate again. As was the case before the seismic station malfunction, seismicity was above background levels at 10 earthquakes per hour. The character of the seismicity indicated that weak ash-and-gas explosions and avalanches possibly occurred. A four-pixel-large thermal anomaly was observed on AVHRR satellite imagery on 9 April , but no ash was detected. The volcano was at Concern Color Code Yellow ("volcano is restless").

During 29 March-2 April, seismicity was above background levels at Karymsky. No seismic data have been available since 3 April due to seismic station malfunction. Faint thermal anomalies were visible on AVHRR satellite imagery on 30 and 31 March. No ash was visible on any satellite imagery. The last assigned Concern Color Code (until 2 April) was Yellow ("volcano is restless").

During 23-29 March, seismicity remained above background levels at Karymsky, with about 10 earthquakes occurring per hour. The character of the seismicity indicated that weak ash-and-gas explosions and avalanches probably occurred. Thermal anomalies that were 1-3 pixels large were visible on AVHRR satellite imagery, but ash was not. The volcano remained at Concern Color Code Yellow ("volcano is restless").

After about one week of instrument downtime, the seismic station near Karymsky began to operate again. As was the case before the seismic station malfunction, seismicity was above background levels (10 earthquakes per hour). The character of the seismicity indicated that weak ash-and-gas explosions and avalanches possibly occurred. Weak thermal anomalies were observed on AVHRR satellite imagery and no ash was detected. The volcano was at Concern Color Code Yellow ("volcano is restless").

Monitoring data showed no signs of volcanism at Karymsky during 8-15 March. No seismic data were available due to seismic station malfunction. No thermal anomalies or volcanic plumes were observed on satellite images. The last assigned Concern Color Code (until 8 March) was Yellow ("volcano is restless").

On 5 March, after 11 days of instrument down time, the seismic station near Karymsky began to operate again. The amount and intensity of seismicity was similar to that recorded in February; about 10 earthquakes occurred per hour. Weak thermal anomalies were observed on AVHRR satellite imagery and no ash was detected. The volcano was at Concern Color Code Yellow ("volcano is restless").

Prior to the failure of the seismic station at Karymsky on 23 February, seismicity was above background levels and similar in comparison to the previous week. During 22 February-1 March, thermal anomalies were visible on satellite imagery. No ash was detected in any images; only steam and possible airborne volcanic aerosols were visible.

The level of seismicity at Karymsky during 15-22 February was similar to the previous week, with about 10 events occurring per hour. Thermal anomalies and small gas-and-steam plumes were visible on satellite imagery. The volcano remained at Color Concern Code Yellow ("volcano is restless").

On 13 February a pilot reported seeing a W-drifting ash cloud rise to 5 km a.s.l. The cloud was not visible on satellite imagery; it may have been a single burst that dissipated rapidly. On 14 February, after 19 days with no seismic data, the seismic station at Karymsky began to work. Local shallow earthquakes occurred at the previously recorded rate of about 10 events per hour. During 8-15 February thermal anomalies were visible on satellite imagery. The volcano was at Color Concern Code Yellow ("volcano is restless").

During 3-8 February thermal anomalies at Karymsky continued to be observed on AVHRR satellite imagery. No seismic data were available due to seismic station malfunction, and no ash was detected in satellite imagery.

Seismicity was above background levels on 25 January, but the next day there were no seismic data available due to a station malfunction. On the 27th a thermal anomaly was visible on satellite imagery. The Tokyo VAAC reported that an eruption on 1 February at 1810 produced an E-drifting ash cloud to ~9 km a.s.l. The cloud was not visible on satellite imagery.

On 19 January a thermal anomaly at Karymsky was observed on satellite imagery for the first time. On 24 January the seismic station, which had been inoperable for the previous 9 days, recorded about 10 local shallow earthquakes per hour. The rate of earthquakes beginning on the 24th was similar to that seen before the station broke, but they became a little stronger over time. No ash was visible on satellite imagery. The Concern Color Code on 25 January was Yellow ("volcano is restless"), which was the same as prior to the seismic station breaking.

During 11-14 January seismic activity at Karymsky was above background levels, with ~200 weak, shallow, local earthquakes occurring per day. Several of the shallow earthquakes indicated possible gas-and-ash explosions. Due to problems with the seismic station, beginning on 15 January, no Concern Color Code was assigned to the volcano. The last assigned Color Concern Code (on 14 January) was Yellow ("volcano is restless").

During 4-11 January, volcanic activity at Karymsky was similar to that of the previous week. Seismicity was above background levels, with 40-80 weak, local earthquakes per day. Several shallow seismic events indicated possible gas-and-ash explosions. Beginning on 10 January at 1200, local earthquakes noticeably increased. The Color Concern Code remained at Yellow ("volcano is restless").

During 28 December-4 January seismicity was mostly above background levels at Karymsky, with 40-80 weak, local earthquakes per day. Several shallow seismic events indicated possible gas-and-ash explosions. The Color Concern Code remained at Yellow ("volcano is restless").

During 21-28 December seismicity remained above background levels at Karymsky, with 60-80 weak, local earthquakes per day. Several shallow seismic events indicated possible gas-and-ash explosions. The Color Concern Code remained at Yellow ("volcano is restless").

During 14-21 December, 50-90 weak local earthquakes occurred per day at Karymsky and several shallow seismic events indicated possible gas-and-ash explosions. Observations from a helicopter on 14 December revealed that the upper part of the volcano's edifice remained snow free and fresh ash covered the volcano's NNW flank and spread ~3 km to Dvor stratovolcano, part of the Karymsky complex.

During 7-14 December, 26-70 weak earthquakes occurred per day at Karymsky, weak spasmodic tremor was registered, and 13 shallow seismic events indicated possible gas-and-ash explosions. Seismicity increased by the end of the week. A pilot reported that on 10 December the upper part of the volcano's edifice was snow free and a gas-and-steam plume was observed. The volcano remained at Concern Color Code Yellow ("volcano is restless").

Since 27 November weak, continuous spasmodic tremor was recorded at Karymsky. From 40 to 60 weak local seismic earthquakes occurred per day. Several shallow seismic events per day indicated possible gas-and-ash explosions. No thermal anomaly was observed.The volcano remained at Color Concern Code Yellow.

A noticeable decrease in seismicity at Karymsky during the end of the week of 16-23 November led KVERT to reduce the Concern Color Code from Orange to Yellow. Seismicity remained slightly above background levels after the decrease in earthquakes and signals of possible ash-and-gas explosions. On 19 November an airline pilot reported that the volcano's edifice looked black. On 22 November KVERT observed that the upper part of the edifice was without snow and had steam emanating from it.

Increased seismicity at Karymsky during 11-16 November led KVERT to raise the Color Concern Code from Yellow to Orange. Beginning on 11 November seismicity was above background levels and many earthquakes and episodes of high-frequency spasmodic volcanic tremor were registered beneath the volcano. On 15 November at 0830 seismicity increased and earthquakes and signals of possible weak ash-and-gas explosions were registered. On 16 November at 0943 a 20-minute-long seismic signal was interpreted to indicate a gas-and-ash cloud may have risen to 8 km a.s.l.

KVERT reported that seismic activity was at background levels at Karymsky until 0905 to 0915 on 20 December when shallow earthquakes registered under the volcano were accompanied by short-lived explosions. At 2150 the same day, a pilot confirmed the presence of ash at the summit of the volcano and mud traces from melting snow on the edifice slopes. On 21 and 22 December (the end of KVERT's report period) seismicity was above background levels. The Concern Color Code was raised from Green to Yellow.

Information is preliminary and subject to change. All times are local (unless otherwise noted)

May 1970 (CSLP 47-70)

Series of powerful eruptions form new crater on 12 May

Card 0943 (22 May 1970) Series of powerful eruptions form new crater on 12 May

A series of powerful eruptions opened a new 200-m round crater at the top of the cone of Karymsky Volcano on . . . 12 May. On 20 May a team of [volcanologists from the Institute of Volcanology] visited the eruption area by helicopter and collected the first rock samples. Within the next few days a new expedition will depart for the volcano and seismologists will make on the spot observations and study the erupting volcano.

June 1975 (CSLP 46-75)

Explosion on 10 May sends plume 1.5 km high

Card 2201 (23 June 1975) Explosion on 10 May sends plume 1.5 km high

The eruption of Karymsky . . . began with a powerful explosion on 10 May 1975. A huge cloud of ash and gas rose to a height of 1,500 m at 0415 GMT, and again on 14 May at 2300 GMT. The explosions were preceded by volcanic tremors recorded since 7 May at the seismic station located 3.5 km from the crater.

Tass reported on 31 July that explosions every 2-3 minutes produced 1-km-high ash clouds, and two lava flows were moving down the flanks.

Information Contacts:Tass News Agency.

October 1982 (Ref 1984)

Lava dome fills crater before being destroyed by explosions

Lava dome growth continued in 1982, filling the crater by mid-year. Small to moderate explosions were frequent January-July. Less frequent but more violent explosions occurred in August and September, then decreased gradually and ended by 10-11 October. The lava dome was destroyed, leaving a bowl-shaped crater similar to that prior to the 1978 eruption.

September 1983 (Ref 1984)

Weak fumarolic activity without seismicity

The following, from Ivanov and others (1984b), was published in SEAN 10:04. [After the eruption ended in October 1982, only weak fumarolic activity, without accompanying seismicity, was observed during the following 11 months. As of September 1983, the summit crater was 160 x 120 m, elongate NE-SW, and post-eruption collapse had deepened it to 60 m (Ivanov and others, 1984).]

On 3 May, Space Shuttle astronauts photographed a feature that appeared to be a short, stubby lava flow extending from the summit crater toward the Pacific coast. The feature was a black area with a length (roughly several hundred meters) 2-3 times its width, and boundaries that were sharply defined against the snow cover. No eruption plume was observed.

The volcano was generally quiet during a 2 February overflight (figure 1). Pre-existing thermal areas were visible in the S and SW parts of the crater, although the vent was snow-covered. Slightly warm zones were also noted on the upper S flank.

Increased seismicity was recorded below Karymsky during 8-14 April, although it is uncertain whether this increase is indicative of an eruption in the near future. A large fumarolic area lies near the summit.

The number of seismic stations has decreased recently, and Kamchatka Volcanic Eruptions Response Team operations are still suspended due to lack of funds.

Periods of seismic unrest have occurred several times in the past 12 months, including one episode in April 1995, and the volcano usually emits a continuous steam plume. Based on recorded seismic activity, an eruption apparently began during 1700-1900 on 1 January. Russian aviation sources reported an ash plume to 7 km altitude at approximately 1130 the next day. A satellite image at 1400 on 2 January showed that the plume had extended at least 200 km SE and S of the volcano. Several aviation notices (SIGMETs) were issued concerning the ash plume. GMS satellite imagery revealed multiple ash emissions on 2 January, with the cloud height estimated at ~7 km. Satellite data on 3 January continued to show multiple low-level (below 5,400 m) ash bursts of short duration that drifted S and dissipated within an hour.

When the volcano was visited by Vladimir Kirianov and Yuri Doubik of the Institute of Volcanic Geology and Geochemistry between 1330 and 1630 on 3 January, they discovered that the initial eruption had vented from the N end of Karymsky Lake. The lake occupies the 5-km-diameter late-Pleistocene Akademia Nauk caldera, ~5 km S of Karymsky volcano proper. However, by the time of their visit activity had shifted to Karymsky volcano where a new crater had formed on the SSW side of the summit, adjacent to the old crater. The new crater, approximately the same size as the old crater, produced explosions every 1-5 minutes that fed a thick black ash plume to an altitude of ~2.5 km moving E. Fresh ashfall was widespread throughout the 5-km-wide Karymsky caldera and for a considerable area to the E and N. Karymsky Lake was yellow-gray in color and mostly covered by steam and vapor. The Karymsky River, which drains the lake to the N, was completely buried in ash and no longer visible; a new beach with numerous fumaroles marked the former source of the river. Very strong seismic activity associated with the eruption included one M 6.5 earthquake on the first day of the eruption. Seismic stations as far as 110 km from the volcano recorded the activity.

By 5 January the new summit crater was over twice the size of the old crater. A thick black ash plume had been observed the previous two days erupting explosively from the new crater to altitudes ranging of 2,400-5,500 m. Seismicity on 6 January indicated continued explosions every 1-3 minutes. Karymsky Lake remained yellow-gray and covered by steam and vapor. Seismicity through 12 January was interpreted to reflect continued, but less explosive, eruptive activity.

Following the main eruptive period in early January, Karymsky had produced one to several small explosions a day. The explosions consisted mainly of steam with minor ash rising to heights <=1.5 km above the summit. Daily explosions continued until at least ~7 March. The lava flow erupted in January stopped growing during early February and continued cooling. The Institute of Volcanic Geology and Geochemistry (IVGG) reported that during the first week of March, Karymsky lake had a temperature of 23°C with a hotter area (32°C) located at its N end.

Ground reports noted one eruptive pulse at 2330 on 29 February; it sent ash and steam to ~4 km altitude; satellite imagery failed to detect this pulse. Simulated trajectory for plumes showed them generally blowing S to SSW.

According to the Institute of Volcanology (IV), the eruption on 2 January began around 0800. This activity was preceded by an upsurge in seismicity that started in April 1995. At 1926 on 31 December 1995, a M 5.8 earthquake occurred in the Kronotsky gulf, 50-60 km NE of the volcano. On 1 January at 2057 an earthquake of M 5.2 in the Karymsky region was followed at 2157 by a M 6.9 event centered ~25 km S of the volcano. During the next day there were more than 10 aftershocks of M >= 5.0. On 2 January at 1540, a group of IV volcanologists arrived by helicopter. Eruptive centers were observed near the summit and 5-6 km S in Karymsky Lake (maximum depth 115 m), which fills the Akademii Nauk caldera.

The eruption began with formation of a vent with a diameter of 20-30 m, located 50 m below the summit. Violent emissions of ash-rich gas jets rose to 1 km from another vent on the SW slope. Steam-and-gas jets, occasionally with black-colored matter, were also ejected to several hundred meters from beneath the surface of Karymsky Lake. The presumed eruptive center was 100-200 m from the shore in the NW sector of the lake. Turbulent steam-and-gas plumes rose 5-6 km above the surface from a 200-m-diameter area. Ice covering the lake had completely melted.

On 3 January the near-summit vent increased in size to 50 m in diameter. Gas and steam blasts alternated with ash ejections from the two simultaneously active vents on the volcano. Ash was usually ejected from the upper vent, and a white-colored plume was emitted from the lower vent. Ash ejections lasted 2-3 minutes, and gas blasts lasted 1.5-2 minutes. An ash-and-gas column rose 1-1.2 km and was blown E and SE by the wind. The surface of Karymsky Lake steamed intensely, sending clouds 800-1,000 m above the lake. Areas of green water were visible through breaks in the clouds, and a newly-formed black beach was seen. In the N and NE sector of the lake a narrow spit, beginning from the source of the Karymsky river and extending 250-300 m to the center of the lake, had formed. The water level in the lake had dropped a few meters. The upper reaches of the river had dried up, but on 2 January waves from the submarine eruption (up to 10 m high or more) overflowed the N shore, flooding a wide valley 1.5 km below the source. During a surveillance flight on 4 January, large areas of the valley were covered by black mud. The beach contained three fumarolic vents along the NE-trending fault zone. Within a radius of 500-800 m of the source of the Karymsky River, the surrounding snow-covered hills contained thousands of holes with diameters ranging from 10 cm to 1.5-2 m formed by lithic blocks ejected from the lake. The water level of the lake continued to fall because of intense evaporation.

Light-gray dacitic ash covered an area of about 150-200 km2. At a distance of 8 km from the volcano fractions ranging from 0.16 to 0.06 mm dominated. Estimates made by S.A. Fedotov indicated that on 2 and 3 January the ash ejection rate from the summit crater reached 3-4 tons/second.

Routine observations from 2 January through 11 February showed that the climactic phase of the subaqueous eruption continued for no more than 12-15 hours. That eruption consisted of frequent explosions during which a vapor-gas mixture with lithic material was ejected to the surface. In the N sector of the lake at the shore W of the Karymsky River, damaged trees provided evidence of two eruptive sources 500-600 m from each other. This zone contained the main concentration of bomb material ejected from the lake. A portion of the shoreline (150-200 m long and 5-15 m wide) E of the river sank several meters into the lake. The main eruption center was 500 m from the shore, but smaller peripheral centers were also observed. As a result of the eruption, in the NNW sector of the lake, a beach in the form of a wide 0.4 km2 cape was produced, as well as a narrow spit extending SE from the old shore. The length of the new shoreline was 2.4 km, and a large shoal was observed around the new peninsula. According to the preliminary estimates, the ejected deposits in the lake are at least 1 km2 in area and 5-10 x 106 m3 in volume.

Thermal springs that discharge at the S shore of Karymsky Lake were destroyed by ejecta from this eruption, and several new mud pots were formed; chemical composition of the solutions was unchanged. Near the center of the new beach, composed of sand-gravel and bomb material, a chain of five explosive vents with diameters from 1.5 to 30 m was observed. At the N end was a thermal site with a diameter of ~50 m that exhibited intense vapor emission and was covered by sublimates; visiting scientists detected a hydrogen sulfide odor. A dry funnel with a diameter of ~3 m and high gas emission at a temperature of 97°C was in the center of this site. Other explosion funnels had water at a depth of 1.2-1.5 m with temperatures from 33 to 70°C. The three funnels closest to the lake and on the opposite shore had gas emissions with temperatures of 97-98°C.

On 4 January run-off from the lake ceased owing to damming by ejected material. Analyses of water samples from the lake, river, and various hot springs in the area indicated that there had been chemical contributions to the lake water by an underlying magma body.

Eruptions continue through April; more details of early January activity

Eruptions began on 2 January from the summit of Karymsky and from the lake (Karymsky Lake) within the Akademia Nauk caldera (figure 2), previously considered to be extinct (BGVN 21:01-21:03). Eruptive activity at [Karymsky] continued through the end of April.

Figure 2. Schematic map showing some features of the SW part of the Karymsky Volcanic Center. Karymsky Lake lies within the Akademia Nauk Caldera. Courtesy of the Institute of Volcanology.

Precursory seismicity. Large tectonic earthquakes in the Kronotsky Gulf have historically been among the precursors to eruptions from Karymsky and Maly Semiachik volcanoes. At 1926 on 31 December 1995, a M 5.6 earthquake occurred in the Kronotsky Gulf (50-60 km NE) at a depth of ~60 km. Earthquake swarms are common beneath the large (50 x 35 km) Karymsky Volcanic Center, but an unusually large swarm started on the evening of 1 January with hypocenters to depths of 80 km (figure 3). These followed a M 5.2 foreshock, and at 2157 a shallow M 6.9 earthquake took place centered ~25 km S of Karymsky; this was the largest earthquake recorded beneath the Kamchatkan volcanoes during the past 50 years. Scientists from the Institute of Volcanology and the Kamchatkan Experimental-Methodical Seismological Department of Geophysical Survey, Russian Academy of Sciences, flew to the epicentral zone of the continuing earthquake swarm and observed the onset of the eruption.

Figure 3. Map and cross-sections of epicenters from the earthquake swarm at Karymsky Volcanic Center that began on 1 January 1996. Cross-section A-B (below map) trends approximately NW-SE, and cross-section C-D (left of map) trends approximately NE-SW. Courtesy of the Institute of Volcanology.

Early eruptions at Karymsky volcano. On the afternoon of 2 January the eruption began on Karymsky's upper SW flank 50 m below the old summit crater and from the Akademia Nauk caldera lake, ~6 km S (figure 4). Ash and gas clouds from the summit vent fed a plume (figure 5) rising to 1 km above the crater; the ash-flow rate was estimated to be several cubic meters per second. The eruption cloud extended E towards the ocean and ashfall was visible 40-50 km away.

Figure 4. Simultaneous eruptions of Karymsky (right) and Akademia Nauk (left) volcanoes, 2 January 1996. Distance between the summit vent of Karymsky and subaqueous vents in the Akademia Nauk caldera lake is 6 km. The Karymsky cone is 700 m high. Courtesy of the Institute of Volcanology.

Figure 5. Continuous gas-and-ash emission from the new vent on the upper flank of Karymsky, 2 January 1996. Courtesy of the Institute of Volcanology.

On the evening on 3 January another crater formed on Karymsky; it looked like a 30-m-diameter amphitheater open to the SW. Sub-vertical Vulcanian explosions occurred from this crater to an altitude of 1 km. Over the next few days, explosions sent gas-and-ash emissions 300-1,100 m high almost every minute.

During the first three days of the eruption, ~500-800 x 103 tons of solid materials, including ash, lapilli, cinder, and bombs, were ejected at Karymsky. During the next 2-3.5 months ~3-4 x 103 tons of andesite-dacite tephra (SiO2 61%) and a small amount of bombs were ejected. An area with a radius of 15-20 km was covered by an ash layer several millimeters thick. The layer's thickness increased along the ashfall axis, reaching 20-30 mm at 4-5 km from the source.

Early eruptions at Akademia Nauk caldera lake. Violent subaqueous explosions on 2 January took place several times every hour in the N part of the 5-km-wide Akademia Nauk caldera lake (figure 6). Explosion clouds rose to 8 km altitude, but most of the tephra fell back into the lake. Ash from Karymsky Lake covered Akademia Nauk volcano and its surroundings. The head of the Karymsky River had its valley and adjacent flood-lands inundated by high water and mud flows.

Figure 6. One of the powerful subaqueous explosions from the N part of Karymsky Lake (Akademia Nauk Caldera), 2 January 1996. The base of the growing cloud is ~1 km wide. Courtesy of the Institute of Volcanology.

Although the Akademia Nauk caldera lake had been ice-covered during the winter, after the January explosions water temperature reached 25°C, pH decreased from 7.5 to 3.1-3.2, and mineralization increased from 0.1 g/l to 0.9 g/l. Thermal water compositionally similar to those of the Karymsky springs started to discharge at a new shoal in the N part of the lake. According to preliminary estimates, ~0.015 km3 of material was supplied to the lake during the eruption.

After the lake water had cleared, a subaqueous deposit around the main explosion vent (with a diameter of 1 km) was observed. The N part of the deposit, ~1 km2, was exposed at the surface, forming an arched spit with the adjoining peninsula (figure 7). According to preliminary estimates, ~5-10 x 106 m3 of tephra including sand and rounded fragments of various sizes, and many bombs, formed the deposit there. Their composition ranged from basaltic andesite to andesite-dacite. The volume of deposits on the bottom of the lake is much greater.

Figure 7. View of Karymsky Lake showing the new 1-km-wide peninsula formed by subaqueous explosion deposits on 2 January 1996. The main vents are to the left of the beach arc. Courtesy of the Institute of Volcanology.

Activity through April. During the ensuing days in January, the eruption style at Karymsky dropped to 5-6 explosions reaching 500-900 m high every hour. More vigorous single explosions were exceptional. On 13-14 January, a block-lava flow from the flank crater traveled 400 m, was 50-70 m wide, and averaged 6-10 m thick. In late January the interval between explosions started to increase from 30 minutes to 2-3 hours.

In February only several explosions were observed each day (figure 8). In late February the number of explosions increased to 5-6/hour, but their intensity decreased. In March the number of explosions decreased but their intensity increased. In April the number of explosions increased. For example, on 23 April they took place every 5 minutes. Two additional lava flows were emitted from the flank crater in April.

A dense geodetic network developed since 1972 at the Karymsky Volcanic Center has been measured repeatedly. During the past 20 years, a horizontal extension of Akademia Nauk caldera was observed that may have indicated filling of a magma chamber under the volcano. Measurements made in February and March revealed an extension of 232 cm along the 3.5-km base and subsidence of 70 cm near the area of subaqueous explosions in the caldera lake.

Karymsky Volcanic Center. Karymsky and Akademia Nauk are part of the 50 x 35 km Karymsky Volcanic Center (sometimes referred to as the Zhupanovsky volcano-tectonic depression). Located in the Eastern Kamchatka volcanic belt, 30 km from the Kronotsky Gulf and Pacific Ocean, this center contains 21 volcanic edifices, six calderas, and two historically active stratovolcanoes, Karymsky and Maly Semiachik.

The 5-km-diameter Karymsky Caldera formed 7,800 years ago and the Karymsky cone has been growing in the center of the caldera for 5,300 years, ejecting andesitic and dacitic materials. Historical reports on Karymsky's eruptions have been available since 1771. During that period of time, more than 20 prolonged eruptions were separated by quiet periods as long as 10 years. The most recent previous eruption continued from 1970 to 1982.

Akademia Nauk caldera, which was named by the famous Russian volcanologist Vladimir Vlodavetz in 1939, is located immediately to the S in the SW part of the Karymsky Volcanic Center. Its activity began about 50,000 years ago. The N part of the caldera is occupied by Karymsky Lake (4 km wide, 12.5 km2 in area, and 80 m deep). The Akademia Nauk chloride-sodium springs, with 1.3 g/l mineralization and temperatures >250°C in the interior part of the hydrothermal system, discharge along the lake's S shore.

Seismicity remained above background in June and the first half of July, and was indicative of continued low-level Strombolian eruptive activity. Gas-and-ash explosions occurred about every 5-20 minutes, generating ash-and-steam plumes to an altitude of 500-3,000 m. Regular reports from KVERT (via AVO) resumed in June after funding problems in Russia halted communications in December 1994 (BGVN 19:11).

Seismicity remained above background in late July and August, and was indicative of continued low-level Strombolian eruptive activity. Gas-and-ash explosions occurred about every 10-25 minutes, generating ash-and-steam plumes to an altitude of 1,800-3,000 m.

During the second half of October and November, seismicity remained above background and was indicative of continued low-level Strombolian eruptive activity. On the afternoon of 13 November, a pilot report indicated vigorous but low-level activity; satellite imagery also showed a well-developed plume traveling ~140 km SE. On 15 November AVO analysis of satellite imagery confirmed a hot spot at the volcano and a plume extending 140 km E.

Although no visual observations were made, during December and 1-20 January seismicity remained above background in a manner that suggested continued low-level Strombolian eruptions. Seismic data indicated that up to 300 explosions occurred each day.

No direct visual observations were made during 25 March-25 April, however the above-background seismicity suggested ongoing low-level Strombolian eruptions. On 14 April an airline pilot reported an ash plume at 6.1 km, but no plume was detected on GMS-5 satellite imagery.

Seismicity remained above background for the three-week interval ending on 27 July. Although visual observations were absent, seismicity indicated continued low-level Strombolian eruptive activity of the kind that has characterized the volcano for more than a year.

On 2 August, V. Kirianov visited the volcano by helicopter and reported continuation of the low-level Strombolian activity that has characterized the volcano for more than a year. A blocky lava flow (60 m wide and 350 m long) was observed moving from the crater down the W slope during 2-10 August. During early August- early October, seismicity remained above background levels. Low-level Strombolian activity continued through mid-October. Gas-and-ash explosions during this period occurred at a frequency of 3-4/hour, with plumes usually rising to 150-600 m, rarely as high as 1,000 m.

During 13 October-24 November seismicity remained above background level; low-level Strombolian eruptive activity that has continued since January 1996 (BGVN 21:01) consisted of gas and ash explosions occurring every 20 minutes, sending ash and steam 200-400 m above the crater. During 24 November- 29 December there was elevated seismicity and explosions every 20-30 minutes that sent ash and steam 300-400 m above the crater. On 14 December, the level of concern was downgraded to yellow from orange, indicating that the volcano's activity was less indicative of a major eruption.

The Kamchatka Volcanic Eruptions Response Team (KVERT) reported continuation of the low-level Strombolian activity that has characterized Karymsky for more than two years. Seismicity remained just above background level. Gas-and-ash explosions during 29 December to 31 January occurred of every 30 minutes, with plumes usually rising 300-400 m. An ash advisory issued by the Washington Volcanic Ash Advisory Center (VAAC) reported an eruption 26 January that produced an ash cloud rising to 3,500 m. No other details of this eruption were available, and satellite imagery did not show evidence of the plume.

Seismicity remained above background level during 2 March-5 April and low-level Strombolian activity continued. As many as 70-100 gas-and-ash or gas-and-steam explosions occurred daily. Ash and steam rose 300-400 m above the crater during the first week of March.

Seismicity at Karymsky remained above background levels during April and May. The low level Strombolian activity characteristic of the past 2 years continues. Violent gas explosions numbered between 70 and 200 daily. Deeper events predominated over explosive events.

Satellite imagery available to the Alaska Volcano Observatory (AVO) showed that on 17 April a long, thin steam plume had extended over 100 km from Karymsky. Also, a distinct thermal anomaly (about 40°C), well above background temperatures, had appeared at the summit 18 April. These features may indicate a small renewal of lava effusion.

Continuing gas-and-ash explosions and lava flow observed during 14-15 July

Through analysis of seismic data, the Kamchatkan Volcanic Eruptions Team (KVERT) detected a change in the volcano's behavior. For the past 2 years, Karymsky characteristically produced low-level Strombolian activity, including more than 100 earthquakes and gas explosions each day. After 10 July the explosive events began to accompany 1-4 minute segments of harmonic tremor.

A visit on 14-15 July disclosed gas-and-ash explosions to heights of 400-600 m above the crater every 8-10 minutes on average. More vigorous gas-and-ash explosions to 1 km occurred about every 2 hours. Lava continued to flow. During the night of 14-15 July, and the following morning, weak ashfall was observed 3.5 km from the crater. Later that morning, a series of ash explosions occurred with a periodicity of ~5 minutes. The color-coded hazard status remained at yellow.

Seismicity remained above background levels during 26 July-1 September. Low-level Strombolian activity, including 100-200 earthquakes and gas explosions each day, continued to characterize activity at the volcano. On 26 July, gas-and-ash explosions reached heights of 400-600 m and occasionally 1,000-1,200 m above the crater every 5-10 minutes on average. Lava continued to flow from the crater (BGVN 23:04 and 23:06). The color-coded hazard status remained at Yellow.

On 5 October, the Kamchatka Volcanic Eruptions Response Team reported that seismicity remained above background level. The low-level Strombolian eruptive activity that has characterized the volcano for more than two years continued. About 100-200 earthquakes and gas explosions occurred every day.

On 24 October Tass reported that a Russian-Japanese expedition of volcanologists had finished their work on Karymsky. The participants had spent two weeks at a location 3 km from the mountain studying seismic, acoustic, and other phenomena related to the eruption.

Seismicity remained above background levels during 1 November-7 December. Low-level Strombolian activity, including 100-200 earthquakes and gas explosions each day, continued to characterize activity at the volcano. On 24 November a pilot in the vicinity reported an explosive event that sent an ash column 6 km above the summit. The color-coded hazard status remained at Yellow.

Seismicity remains elevated. The low-level Strombolian eruptive activity that has characterized the volcano for the past two years continued during December. About 300-400 earthquakes and gas explosions occur every day. Satellite imagery on 16 December showed an ash-poor plume extending 200 km E. No change in seismicity was noticed. The level of concern color code remained yellow.

The low-level Strombolian eruptive activity that has characterized Karymsky for more than two years continued during January. About 300-400 earthquakes and gas explosions occur every day. The color-coded alert level continued at yellow.

Satellite imagery obtained by Alaska Volcano Observatory from 14 January showed a strong thermal anomaly on the volcano, but no change in seismicity was noticed. Seismic information for 28-31 January was not available owing to technical problems.

Seismicity remained above background during February and March, and the Level of the Concern Color Code remained at Yellow. Low-level Strombolian eruptive activity that has characterized the volcano for more than 3 years continued with ~150-200 daily earthquakes and gas explosions.

An ash plume observed on 10 February rose ~5 km above the summit. Satellite images on 15 and 17 February showed a thermal anomaly. Small earthquakes close to Karymsky Lake began to be recorded on 7 February. According to a pilot's report, an ash plume on the morning of 25 February rose as high as 3,500 m.

The low-level Strombolian eruptive activity that has characterized the volcano for more than three years continued from 24 May through 26 July. Earthquakes and gas explosions ranged over 25-70/day until 5 July when seismicity began decreasing to just above background levels. During the week of 5 July to 12 July, the number of earthquakes and gas explosions decreased to ~5-10/day. Probable pyroclastic flows occurred on 24 and 25 July. Overall activity continued to decrease and on 2 August, after more than 3 years of eruptive activity, the volcano returned to its normal state.

However, on 5 August, seismicity under the volcano increased and more than 70 weak to moderate gas explosions were recorded. On 7 August, after 10 days of quiescence, eruptive activity was renewed and the number of explosions exceeded 300/day.

Eco-tourists visited the volcano between 8 and 10 July (guided by Guy de Saint-Cyr of Aventure et Volcans of Lyon, France and Alexei Choustrov of Top Sport Travel, St. Petersburg, Russia) and reportedly made helicopter flights above the crater and a landing at their base camp. For 8 July the group reported no visible activity in the central crater and a very viscous lava flow (Merapi type) with some incandescent zones escaping from the collapsed part of the crater. But at 1705 on 9 July, they noted a violent detonation with simultaneous explosions on the two summit craters and a ~200-m-diameter eruptive column rising vertically to ~700 m altitude. All of Karymsky volcano disappeared under an ash cloud with a shower of 1-m3-sized blocks crashing down and rolling to the foot of the cone and halting less than 100 m from their base camp. According to their report, from 2000 on 9 July to 0600 on 10 July, an active lava flow accumulated at the foot on the W side of the crater.

The low-level strombolian eruptive activity that has characterized the volcano for more than three years gradually decreased after August until seismicity returned to background levels, and by late December there were no explosions. The eruption began on 2 January 1996 (BGVN 21:01) following an eruption from the Akademia Nauk caldera lake the previous day.

During the week of 9-15 August, steam-and-ash plumes were observed in satellite imagery extending as far as 75 km downwind at an altitude of 500-1,000 m above the crater. The number of gas-and-ash explosions was still more than 300/day the next week, with the plume rising 300-600 m above the volcano. During the last week of August through 5 September, the number of explosions was more than 75/day, with plumes to heights of 300-1,000 m above the volcano. Visual observations by KVERT staff on 1 and 5 September confirmed that explosive activity occurred every 10-20 minutes.

The number of gas-and-ash explosions decreased from 130 on 6 September to 80 on the 12th, but the plumes continued to rise 300-1,000 m above the volcano. That rate continued until the week of 20-26 September, when the average number of daily explosions decreased to 60. The number of explosions was 60-75/day during the next two-week reporting periods, through 10 October. During the week of 11-17 October the explosion rate decreased once again, to 20-35/day, although plume heights remained at 300-1,000 m. The number of explosions increased slightly, to 20-50/day, during 5-18 November, but then dropped the following week to 10-20/day and then only 2-5/day. During the week ending on 2 December, gas and ash explosions numbered 1-10/day.

The nearest seismic station (KRY) was out of order during 4-18 December. According to the regional seismic network, no strong events occurred during that period. The station was restored to operation on 19 December. As of 30 December seismicity at the volcano had decreased to background levels. About 1-2 local earthquakes occur every day and the volcano has returned to its normal state. At the end of December seismicity was at background levels of about 1-2 local earthquakes/day.

This report covers the period from January-April 2000. As of 28 April 2000, KVERT (Kamchatkan Volcanic Eruption Response Team) temporarily suspended operations because of a lack of funding. Throughout January and early February, seismicity was at background levels with about 1-5 small local earthquakes each day. However, after two months of quiescence, seismic activity beneath the volcano renewed at 0635 on 12 February; seismic data indicated the occurrence of a probable, short-lived gas-and-ash (or gas) explosion as a 5-minute-long seismic signal was recorded by the nearest seismic station (KRY). As a result of this activity, the hazard level was raised to Yellow.

Following this event, an average of 5-10 seismic events/hour occurred, mainly corresponding to explosions along with a few blowouts and pyroclastic flow (?) signals. After 1200 on 15 February, seismicity increased to 40 events/hour. A continuous series of seismic events (pyroclastic flows?) were registered from 1620 to 1810 on 15 February, but satellite images at 1715 and 1855 that day did not show a plume rising above the weather clouds at ~4 km altitude. From 1800 on 15 February to 1340 on 16 February, activity varied from 40-60 events/hour at the end of which a new 80-minute-long series of seismic events was registered. Subsequently, during 1500-1750, 200 events occurred and, at 1750, strong low-frequency, 4-minute-long events were registered. Activity decreased from 40 to 20 events/hour from 1800 on 16 February until 1200 on 17 February. A satellite image from 0630 on 17 February, the first clear image that the Alaska Volcano Observatory had received since the increase of activity on 12 February, showed no plume, but a thermal anomaly covered at least four pixels with a maximum temperature of 40°C.

The low-level Strombolian eruptive activity that has characterized the volcanism for much of the past four years continued for the remainder of February and throughout March. The number of gas-and-ash explosions decreased from 600/day to 25/day during late February. From 1230 to 1620 on 18 February weak volcanic tremor was registered. According to pilot reports on 20 and 21 February, these explosions sent material up to 1,500 m above the volcano. The number of gas-and-ash explosions varied from 5 to 300/day (although 5-50/day was most typical) through March; suspected small pyroclastic flows were occasionally detected.

At 0625 and 2336 on 3 April and 0743 on 4 April, seismic data indicated short-lived ash-and-gas explosions more intense than those previously recorded. These explosions probably occurred during 3-6-minute-long seismic events recorded by the nearest seismic station (KRY). However, during the following week, no more than three small events/day were recorded and the hazard level was returned to Green. This level of activity continued through April with occasional 2-15-minute-long seismic events, related rock avalanches, and possible short-lived explosions.

This report covers Karymsky's activity from June through mid-October 2000. KVERT (Kamchatkan Volcanic Eruption Response Team) resumed reports at the beginning of June after a month-long shutdown due to funding deficiencies. The seismic events per day and number of explosions varied throughout the period, but decreased to background levels by the end of September. On 10 June, 25 short-lived weak explosions occurred, although the average number of explosions per day during that week remained low. During 19-29 June, seismicity increased when up to 17 events occurred per day. The number of weak explosions also increased during 19-29 June when up to six explosions occurred per day. On the afternoon of 25 June intense explosions were recorded that suggested a pyroclastic flow. Other than this, no significant volcanic activity occurred. KVERT maintained the Level of Concern Color Code at Green for the entire interval.

Since the activity reported from June through mid-October 2000 (BGVN 25:09), the Kamchatkan Volcanic Eruption Response Team (KVERT) reported that seismic activity at Karymsky remained mostly at background levels, with a few episodes of increased seismicity.

On 20 December 2000 around 0915 shallow earthquakes under the volcano were accompanied by short-lived explosions. At 2150 the same day a pilot confirmed the presence of ash at the summit of the volcano and mud traces from melting snow on the edifice slopes. The Concern Color Code was increased from Green (volcano is dormant; normal seismicity and fumarolic activity) to Yellow (volcano is restless; eruption may occur) until 29 December.

On 2 and 28 February several shallow seismic events took place, including a 5-minute-long series of weak shallow earthquakes on 28 February. During March, small shallow earthquakes and one episode of weak high-frequency spasmodic tremor were registered. On 12 March a high-frequency signal lasted for 90 minutes. On 28 March, from 1205 to 1300, an intense series of earthquakes with magnitudes up to ~3 was registered. Several local low-frequency earthquakes occurred during the end of March and beginning of April. Around 20 April, more than 40 earthquakes with magnitudes up to ~2.5 occurred. Since then through at least September 2001, seismic activity at Karymsky has remained at background levels with the exception of 23 August, when 30 earthquakes were registered.

Episodes of increased seismicity occurred during December 2000 through September 2001 (BGVN 26:08). Since then seismic activity at Karymsky has remained mostly above background levels. The Concern Color Code remained at Yellow ("volcano is restless") through at least late March 2002. Apparent steam plumes were seen in satellite imagery during January-March 2002.

On 4 January 2002, the Kamchatkan Volcanic Eruption Response Team (KVERT) reported above-background seismicity during the previous week, with 40 to 80 weak local earthquakes occurring per day. Several shallow seismic events suggested gas-ash explosions. Beginning at 1200 on 10 January the number of local earthquakes increased noticeably. During 11-14 January about 200 weak local shallow seismic events occurred per day.

During late January through at least March 2002, the seismic station typically recorded approximately 10 local shallow earthquakes per hour. Around 24 January, the earthquakes became slightly stronger. The character of the seismicity during mid-March suggested weak ash-gas explosions and avalanches.

The Tokyo VAAC reported that on 1 February at 1810 an eruption produced an ash cloud that reached ~7.5 km above the summit and drifted to the E; however, the cloud was not visible on satellite imagery. On 13 February at 0945 a pilot reported an ash cloud to ~3.5 km above the volcano extending to the W. Again, this cloud was not visible on satellite imagery; it may have been a single burst that dissipated rapidly.

No ash was detected in satellite images during the report period; only steam and possible airborne volcanic aerosols were visible during late February. Thermal anomalies and plumes were visible on AVHRR satellite imagery throughout the report period (table 1).

Table 1. Thermal anomalies and plumes visible on AVHRR satellite imagery at Karymsky during January through March 2002. Courtesy KVERT.

Seismicity at Karymsky was above background during late March through at least mid-July 2002. Local shallow events occurred at the same rate previously reported in BGVN 27:03 (~10 events per hour). The rate increased briefly during mid-May to ~10-15 events per hour. The character of the seismicity indicated that weak gas-and-ash explosions and avalanches possibly occurred. Thermal anomalies and occasional plumes were visible on satellite imagery throughout the report period (table 2).

Table 2. Thermal anomalies and plumes visible on AVHRR satellite imagery at Karymsky during 30 March-9 July 2002. No airborne ash was detected in any image. Courtesy KVERT.

According to a pilot's report, at 1115 on 15 April an explosion ejected ash to a height of 3.0 km above the volcano. MODIS imagery on 17 April revealed at least five traces of ashfall extending to ~25 km in various directions.

During a helicopter flight on 28 April, observers reported an ash explosion to 500 m above the crater. Ash deposits were visible on the W (most intense) and E flanks of the volcano. A new ~100-m-high cone was visible on 28 April inside the active crater.

On 10 May the new cone was visible along with a lava flow 1.3 km down the S-SW slope of the volcano (figure 9). It reached ~300 m wide. The flow was unusual because it had an andesitic composition, rather than the typical basaltic composition that was common in lava flows down the SW flank during 1996-2000. Seismic data on 29 June indicated a possible ash-and-gas explosion to a height of ~4.0 km at 1631. On 9 July at 1032, a helicopter pilot reported a plume to a height of 3.0 km. The Concern Color Code remained at Yellow throughout the report period.

Figure 9. View of Karymsky from a helicopter on 10 May 2002. The billowing plume at the time of this photo concealed the new intracrater cone at the summit; winds carried the plume approximately ENE. The active crater generated a conspicuous lava flow down the S-SW slope that reached ~1.3 km long and ~300 m wide (~ 20% of its length continued beyond the lower right-hand margin of this photo). Caption help courtesy of Victor Ivanov (Institute of Volcanology). Photo by Nikolay I. Seliverstov (Institute of Volcanology); provided courtesy of KVERT.

3-km-high plumes, seismicity, and three new lava flows through September 2002

Frequent plumes (including 15 April and 9 July ash clouds to 3.0 km above the volcano), a new intracrater cone, and a 1.3-km-long lava flow were seen during 1 January-9 July 2002 (BGVN 27:03 and 27:06). This report first highlights events described in 10 July-September 2002 updates. During this interval Karymsky produced 3-km-tall plumes, restless seismicity, and three new lava flows. Next, a separate section of this report presents photos of Karymsky and adjacent Akademia Nauk caldera taken in September 2000 and in May 2002. This report also cites a fundamental reference volume on the topic of the 1996 eruption, Fedotov (1998), which includes a preface and ten papers.

Activity during 10 July-September 2002. Seismicity during this interval generally stood well above background levels, very often at a value of ~10 earthquakes per hour. During nearly every week of the reporting interval, geophysicists suggested that the character of the seismicity might indicate weak ash-and-gas explosions and avalanches. Weak thermal anomalies were often observed on AVHRR satellite imagery and, in the majority of cases, no ash was detected. In contrast, satellite imagery on 25 July indicated a possible, small, SW-directed ash plume. On 26 July, a thermal anomaly reached 2 pixels in size.

During 27 July-2 August, local, shallow seismic events decreased, dropping from 250 to 150 events per day. During 30 August-6 September and 13-24 September there were 200-300 local shallow earthquakes occurring per day (compared to 150-250 per day in August). In early September estimates suggested that explosions rose ~1 km above the summit.

Observations on 8 September revealed three new small lava flows on the volcano's S and SE slopes. On satellite imagery a thermal anomaly was visible but ash was not. The character of the seismicity indicated ash-and-gas explosions rising ~1 km above the volcano and gas blow-outs. On 16 September at 1217 a short-lived explosion created an ash-and-gas plume; observers on an aircraft aloft estimated the plume top's height at ~3 km altitude.

Photographs and brief retrospective on the 1996 eruption. Figures 10 and 11 provide overviews of the Karymsky stratovolcano (also written as Pra-Karymsky) and adjacent areas to the S on 26 September 2000 and 10 May 2002 respectively. Both these aerial photos were provided by Victor Ivanov (Russian Academy of Sciences). The former was taken ~4 years after the complex 1996 eruption (see BGVN 21:01-21:03 and 21:05; and Fedotov, 1998).

Figure 10. An aerial photo taken on 26 September 2000 looking towards the SSE and showing Karymsky stratovolcano (cone on the right), the low-lying portion of Akademia Nauk caldera containing Karymsky lake (in the upper center of the photo), Karymsky river (bright, light-colored zone cutting diagonally across the center and left), and Belyankin volcano (arc-shaped, in the upper-right corner). Prominent cliffs, part of the N-facing amphitheater of Dvor volcano, curve across the terrain well outboard of the stratovolcano (lower left-hand margin). The Karymsky river drains the lake from an outlet at the head of a conspicuous bay. The distance from the cone's summit to the lake's nearest margin is ~ 5 km. Courtesy of Victor Ivanov.

Figure 11. An aerial photo with Karymsky stratovolcano in the foreground, shot looking towards the S on 10 May 2002. Snow blankets considerable areas and ice covers Karymsky lake. During 1996-2000 many lava flows covered the stratovolcano's SW slope. On 10 May there were fresh andesitic lavas descending the W flank reaching ~ 1.3 km in length and ~ 300 m in maximum width (labeled "2002 lavas" and "Front"). Haze in this photo is partly due to erupted ash suspended in the atmosphere. A separate photo the same day captured Karymsky with a billowing, light-colored plume (figure 9 above). Courtesy of Victor Ivanov.

In overview, that eruption consisted of a 1 January 1996 earthquake swarm (with events to M 6.9) followed a day later with simultaneous eruptions from two vents 6 km apart, one at the stratovolcano's summit, the other at Akademia Nauk caldera in the N end of Karymsky lake. The latter consisted of a submarine phreatomagmatic eruption that deposited a low conical ring composed of pyroclastics. The subaerial portion of those deposits encircled the vent forming a ~600-m-wide crater in the cone's center. The cone also extended to the lake shore, thus forming a peninsula. The eruptive event included or was associated with base surges, tsunamis, surface ruptures, and secondary eruptions on the new peninsula. The eruption also left the lake with pH of 3.2 and its outlet into the Karymsky river obstructed by the new deposits. Several months later the new deposits eroded, resulting in massive mudflows down the Karymsky river. At the submarine vent eruptive products were predominantly basaltic; some fine ash was andesitic; late-stage rhyolites occasionally formed inclusions within basalts and bombs with basaltic jackets.

The photos were taken from perspectives on the volcano's N side. Several months after the dam-breaking event, the partly eroded pyroclastic deposits took the form of a squat U-shaped peninsula with two arms extending hundreds of meters into the lake. The circular segment along the middle of the peninsula's shoreline is part of the original cone's arcuate rim. Towards the left of the peninsula lies a conspicuous bay that leads to the outflow channel and the Karymsky river (the latter is most apparent on figure 10). Figure 11 shows that two years later the pyroclastic deposits in the lake more closely resemble lines rather than broad zones due to the partial cover of ice and snow.

The 1996 eruption at Karymsky and the Akademia Nauk caldera may have been a response to the injection of fresh basaltic magma from a deeper magmatic source. Later stages of the eruption at Karymsky have continued more than 6 years through this reporting interval.

During the underwater eruption in 1996 all of the lake's ice was broken and melted. Along the lake shore many new hot springs appeared. After the underwater eruption on the bottom of the lake many sources of heat and degassing appeared. The eruption triggered an ecological catastrophe during which all fish in the lake died.

During the winter 1996-1997 the water of the lake remained warm and devoid of ice. Usually ice completely disappears only in June or July. Lake ice returned in subsequent winters. Figure 10 (26 September 2000) shows light-colored patterns on the lake's surface that signify the presence of local ice accumulating there with the approach of winter. Figure 11 documents the dominance of ice on Karymsky lake's surface, still intact from the previous winter when photographed. The May 2002 lake surface also contained some ice-free zones. Their presence suggested the continued existence of post-eruptive heat sources on the lake bottom. These areas were possibly rich in algae and micro-organisms.

According to the Kamchatka Volcanic Eruptions Response Team (KVERT), the alert level Color Code remained at Yellow (volcano is restless; eruption may occur) from October 2002 to 27 February 2003, when it was dropped to Green (volcano is dormant; normal seismicity and fumarolic activity). The level was raised again to Yellow in March, lowered to Green on 29 March, and raised to Yellow on 18 April, where it remained through May. Seismicity was above background levels until 20 February, after which it fluctuated between at and above background levels until 16 May, when seismicity remained above background levels. All times are local (= UTC + 11 hours, + 12 hours after 26 October).

Activity during October 2002. From 4 to 31 October, ~200-250 local shallow seismic events occurred per day. The character of the seismicity indicated ash-and-gas explosions to heights of 1,000 m above the volcano (~2,500 m altitude) and gas blow-outs. A faint 10-km-long plume extending SSE was visible in an AVHRR satellite image; no ash was detected. Seismicity on 25-26 October indicated possible vigorous gas emissions lasting 5-10 minutes, with the probability of a lava flow. At 1350 on 31 October, pilots reported that an ash plume rose 4 km and extended SE. According to seismic data from the Kamchatka Experimental and Methodical Seismological Department (KEMSD), the character of seismicity after 1400 on 31 October indicated a moving lava flow. At 1314 on 31 October, the MODIS satellite image showed a large bright thermal anomaly at the volcano and a plume ~60 km long that extended WSW. At 1100 on 1 November, pilots reported that an ash plume rose 4 km and extended SE.

Activity during November 2002. Local shallow seismic events totaled ~200-250 each day. The character of the seismicity indicated ash-and-gas explosions to heights of 1,000-2,000 m above the volcano and vigorous gas emissions lasting 5-10 minutes. At 1605 on 1 November, a 50-km-long plume was observed extending E in satellite imagery; no ash was detected. According to data from KEMSD, at 2357 on 20 November, a seismic event lasting 20 minutes indicated that ash explosions to heights of 1,000 m above the crater and hot avalanches possibly occurred. On 27 November, a >100-km gas-and-steam plume extending ESE from the crater of the volcano was observed in MODIS satellite imagery. Helicopter observations by KVERT scientists at 1151 on 1 December identified an ash plume to ~500 m above the crater extending SE.

Activity during December 2002. Local shallow seismic events totaled ~190-230 each day. The character of seismicity indicated that ash-gas explosions to heights of 1,000 m above the volcano (~2,500 m altitude) and vigorous gas emissions lasting 5-10 minutes were possibly occurring. The top of the volcano and its SE flank were covered with recent ashfall and debris from continuing Vulcanian / Strombolian eruptions. The old crater was covered by the new cinder-ash cone. On 12 December, two sectors of ash falls extending S and SE from the volcano were noted in a MODIS satellite image.

Activity during January 2003. Local shallow seismic events totaled ~110-200 each day. The character of seismicity indicated that ash-gas explosions to heights of 1,000 m above the volcano (~2,500 m or 8,200 ft. ASL) and vigorous gas emissions lasting 5-10 minutes were possibly occurring. From 1559 until 1609 on 8 January, a series of shallow events that possibly indicated hot avalanches were registered. On 9 January, a ~50-km plume extending ESE from the volcano was noted.

Activity during February 2003. The alert level Color Code remained at Yellow until 27 February, when it was lowered to Green (volcano is dormant; normal seismicity and fumarolic activity). According to satellite data from Russia, a weak thermal anomaly was noted on 3 February. Seismic activity was at background levels on 20-23 February.

Activity during March 2003. The alert level Color Code was raised to Yellow as the activity of the volcano slightly increased. Seismic activity was at background levels on 13-18 March and slightly above background levels on 19 March when seismic data indicated possible hot avalanches. Weak volcanic earthquakes were also registered on this day. According to MODIS-satellite data from Russia and the USA, ash deposits extending more than 30 km SW from the volcano on 17-20 March and gas-steam plumes drifting more than 15 km NW and SW on 18 March and on 20 March, respectively, were noted. Seismic activity dropped to background levels for the week of 20 March. According to satellite data from Russia, a weak thermal anomaly was observed on 25 March, and a gas-and-steam plume extending 10 km ESE was noted on 28 March. According to helicopter observations on 31 March by the Institute of Volcanology (IV), Far East Division, Russian Academy of Sciences, the large old active crater of the volcano and its black ESE flank were noted, but the new cinder-ash cone was not seen. This cone was probably destroyed and its products formed ash-deposits extending >35 km ESE, which were noted on the 17-18 March MODIS-satellite images.

Activity during April 2003. The alert level Color Code was dropped to Green during the week of 29 March-4 April, when seismic activity was at background levels. Seismicity rose above background levels during the week of 18-24 April, when ~40-100 volcanic earthquakes per day were recorded, and the hazard status was raised to Yellow. The character of the seismicity indicated ash-and-gas explosions up to 1,000 m above the crater. According to satellite data from Russia, ash deposits up to 35 km or longer extended in different directions on 19-22 April. According to observers from IV, on 18-24 April occasional ash-gas explosions up to 2,500 m above the crater occurred each day, and on 21 April, an ash-gas plume rose 1,500 m. Seismic activity was above background levels on 24-27 April and at background levels on 27-30 April. During 24-26 April 50-100 volcanic earthquakes per day were registered. The character of the seismicity indicated that three eruption events (possibly ash-and-gas explosions and rock avalanches) occurred on 24 April. According to satellite data from Russia, wide ash deposits longer than 35 km and three narrow ash deposits less than 5 km long extending SE and W and SW from the volcano, respectively, were noted on 25 April and 28-29 April. According to observers from IV FED RAS, on 24 April, an ash-gas plume rose 2,500 m above the crater.

Activity during May 2003. The alert level Color Code remained at Yellow for the month, with intermittent explosive eruptions continuing. Occasional explosions up to 1,500 m above the volcano, producing ash, were considered to be possible, as well as ashfall within a few tens of kilometers. Seismic activity was at background levels during 3-16 May. According to satellite data from Russia, the summit of the volcano was black on 4 May. For the week of 10-16 May, seismic data indicated that 10 ash-and-gas explosions reached heights up to 1,000 m above the crater, and hot avalanches possibly occurred. According to satellite data from the USA and Russia, a weak 1-pixel thermal anomaly on 14 May, and strips of ash deposits extending >10 km to the S, SSE and SE on 14-15 May were noted. Seismicity was above background levels on 16-30 May.

During 18-21 May, 150-320 local shallow events occurred per day. The character of the seismicity indicated ash-and-gas explosions to heights of 1,000 m above the volcano, gas blow-outs and hot avalanches. According to satellite data from the USA and Russia, a 2-4-pixel thermal anomaly was observed during 18-22 May. Ash deposits on snow E and SE of the volcano were noted on 18 May. Gas-steam plumes extending up to 45 km NE and N of the volcano on 19 and 21 May were noted. For the week of 24-30 May, 280-330 local shallow seismic events occurred per day. The character of the seismicity indicated ash-and-gas explosions to heights of 1,000 m and gas blow-outs. A thermal anomaly continued to be observed. On 25-26 May, gas-and-steam plumes extending 15-115 km SSE from the volcano were noted. Ash deposits on the snow in a different direction from the volcano were noted on 26-27 May.

Dark ash was observed on the NE, SE, and W flanks of the volcano on 30 May in a MODIS (moderate resolution imaging spectroradiometer) Terra image. Intermittent explosive eruptive activity at Karymsky occurred from early June into mid-August 2003, with seismic activity above background levels. Between 90 and 270 local shallow events occurred per day. The character of the seismicity indicated that ash-and-gas explosions to heights of 1,000-2,000 m above the volcano (2,500-3,500 m altitude) and gas blow-outs possibly occurred. On the morning of 17 July a strong, long duration (86 minutes), seismic event occurred that possibly resulted from a large pyroclastic flow or the onset of a new lava emission. Satellite data confirmed the continuing activity (table 3).

From late August through 5 December seismic activity at Karymsky was above background levels (100-230 events per week) and intermittent explosions continued. The Level of Concern Color Code was Yellow through most of September and October, with a week at the higher Orange status during 3-10 October. The color code was raised to Orange again on 31 October and remained at that level through 5 December. Thermal anomalies identified in satellite data were usually 1-4 pixels in size, with a maximum of 6 pixels on 30 August, and 10, 11, 14, and 16 October. However, the weather was frequently cloudy after 12 September, obscuring observations.

Ash explosions rising up to 4.0 and 4.7 km were observed from aircraft on 29 August. About 2 hours of continuous spasmodic tremor (6.0 x 10-6 m/s) on 30 August, followed by the detection of a thermal anomaly (6 pixels) less than an hour later, may have been caused by a pyroclastic flow.

On 9 and 10 September, continuous high-frequency spasmodic tremor and a series of shallow seismic events indicated possible ash-and-gas explosions to heights of 1.5-2.0 km above the volcano. A gas-and-steam plume extending 100 km E was noted on 9 September. On 14 September an ash-and-gas plume was seen rising 500 m above the crater. On 23 September there was an explosive ash plume up to 5 km altitude according to visual data from the Institute of Volcanology.

The number of shallow seismic events increased during 4-24 October to weekly highs of 350; these events indicated possible ash-and-gas explosions to heights of 1-1.5 km. Ash plumes extending 60 and 30 km SE and NE were observed on 4 and 7 October, respectively. An extensive gas-and-steam plume extending 85 km SE was noted on 10 October. Continuous high-frequency spasmodic tremor detected for almost an hour on 10 October probably indicated pyroclastic flows. Ash plumes extending 45-50 km NW were observed on 16 October. On 31 October, a possible plume extending ~65 km NNE was observed in a satellite image. Gas-and-steam plumes with possible minor ash ~40-60 km long were detected on 20, 21, 24, and 26 November; clouds obscured the volcano on other days.

The intermittent explosions and elevated seismicity reported in BGVN 28:11 continued through December 2003. The Tokyo Volcanic Ash Advisory Center (VAAC) reported, for the period 28 November-5 December, that intermittent explosive eruptions emitted ash up to ~ 3.5 km altitude. The Kamchatkan Volcanic Eruption Response Team (KVERT) reported on 12 December 2003 that intermittent explosive eruptive activity at Karymsky was continuing, with occasional explosions sending ash up to 3.5 km above the volcano and local ashfall possible. Seismicity was above background levels, with 200-250 shallow long-period events per day during the previous week and possible ash-gas explosions rising up to 1-1.5 km above the volcano. Seismic data showed, at 0745 on December 5, a possible ash-gas explosion up to 4 km. Satellite data from 5-10 December showed a 1- to 5-pixel thermal anomaly over the volcano.

KVERT reported similar conditions for the week ending 19 December, with ash to 1-2.5 km above the crater and 160-240 events per day. On 16 December, they reported possible ash plumes up to 3 km above the crater and 1- to 5-pixel thermal anomalies on 11-17 December. These conditions continued during the week ending 26 December, with seismic events fluctuating at 40-200 per day and ash-and-gas plumes rising 1-2 km over the volcano. The number of earthquakes decreased during 18-20 December and increased during 21-24 December, with probable ash explosions to 3.5 km on 21 December.

At 0359 on 23 December and 1605 on 24 December possible explosions with pyroclastic flows were recorded. A 1- to 3-pixel thermal anomaly was observed by satellite on 21-22 and 24-25 December. For the week ending 2 January 2004, local shallow earthquakes took place 200-270 times per day with possible ash-gas explosions to 2-3.5 km. Possible explosions accompanied by pyroclastic flow were recorded on 25, 29, and 31 December; a 1- to 4-pixel thermal anomaly was also observed. On 29 December a very narrow gas-steam plume extended 97 km SE. The color code alert remained at orange during the month.

Intermittent explosions and seismicity above background levels, as also reported in BGVN28:11, continued from 1 January to mid-April 2004, a time interval when the Level of Concern remained at Orange. Occasional explosions occurred without warning, sending ash as high as ~ 7000 m altitude and yielding ashfall locally and beyond the volcano. Ash deposits were detected extending in essentially all directions on various days during the report period. Clouds frequently obscured visual observation of the volcano.

During January 2004 the daily number of local shallow earthquakes varied from lows of 40-80 to highs of 200-300. Similarly, in February, shallow events varied from lows of 30-40 to highs of 160-200. However, in March, particularly after the early part of the month, the highest daily numbers rose to 240-380. The highest daily numbers reached still higher during April, to as high as 300-470.

Up to five ash-gas explosions occurred on specific days during each month. These explosions sent plumes to altitudes of ~ 3-5 km during January (although pilot reports sometimes estimated higher plumes, to 5.5 to 7 km altitude). Plumes rose to ~ 2.5-6.5 km during February and March, and dropping to ~ 2.5-3.5 km during April. Thus, although more daily earthquakes occurred during April, the plume heights then appeared lower than in January-March.

During the week ending 16 January, an ash plume observed by pilots of a local airline rose to 7 km altitude and extended to the S-SW. Pilots also reported ash plumes rising up to 5.5 km altitude on 9 and12 February. On 11 February, an ash cloud rose to 10 km altitude and drifted 60 km from the volcano. Reports describing 20 February noted ash deposits extending about 35 km S.

According to satellite data from the USA and Russia, thermal anomalies of 1-4 pixels were observed during January and 1-6 pixels during February and March. However, the number of pixels increased from 1 to 10 during early April, the same period when the number of shallow earthquakes was increasing.

During 1 January to mid-April 2004 (BGVN 29:04), ash-and-gas explosions and gas plumes were observed and seismicity remained generally above background levels. From May to the beginning of September 2004, seismic activity remained above background levels, varying over this time from 100-800 small shallow earthquakes per day. Ash-and-gas explosions and gas plumes to a maximum height of 7.5 km were frequent. On 1 September 2004 an increase in activity led the Kamchatka Volcanic Eruptions Response Team (KVERT) to raise the Concern Color Code from Yellow to Orange. From September to December 2004, seismicity remained above background levels, and ash-and-gas explosions and ash plumes were frequent. On 12 November the hazard status was lowered to Yellow.

Increasing seismicity, rock avalanches and possible ash plumes to 2.5 km altitude led KVERT to raise the Concern Color Code to Orange again on 7 December 2004. On 28 December, an observed eruption at Karymsky produced a plume composed primarily of gas and steam, but with some ash, that rose to ~ 1 km above the crater. Thermal anomalies were also visible on satellite imagery on 27 and 28 December. On 30 December the Tokyo VAAC reported that a plume was present up to ~ 8 km altitude extending SW.

There were no seismic data from 12 December 2004 till late January 2005. Through January and February thermal anomalies were frequently visible on satellite imagery. Seismicity remained above background levels from February 2005 through July 2005.

Through March and April 2005, ash-and-gas explosions and gas plumes were frequent. Ash deposits extended 10-15 km S and SW of the volcano. On 20 April, volcanic bombs rose to 50 m above the crater, and ash fell to the NE on 21 April. On 26 and 27 April, Strombolian activity was seen in two of the volcano's craters; volcanic bombs rose to ~ 300 m above the craters. Ash fell to the SE on 22-23 April and pyroclastic-flow deposits were seen on the NNW flank of the volcano. During May 2005, ash-and-gas explosions and plumes were again frequent, and a thermal anomaly continued to be visible on satellite imagery.

Due to a decrease in seismic and volcanic activity during 3-10 June, KVERT decreased the alert level from Orange to Yellow. Seismic activity increased starting on 22 June. Ash explosions up to 3,000 m altitude traveling SW were observed by pilots. According to seismic data, about 10 ash-and-gas plumes and avalanches occurred at the volcano. On 23 June KVERT increased the alert level to Orange. Satellite imagery of Karymsky showed a narrow ash-and-gas plume at a height of ~ 3.5 km altitude on 30 June. Based on interpretations of seismic data, ash-and-gas plumes may have reached 3 km above the crater.

The Tokyo VAAC posted four messages on Karymsky during the 90 days prior to 8 August 2005; in each, ash was not identifiable from satellite. The earliest, 18 May was similar to the last one, on 23 June. Both noted a reported plume to FL100 ('flight level 100' signifies 10,000 feet; 3.05 km altitude). Reports on 22 and 24 May both noted ash to FL 120 (3.65 km altitude).

From December 2004 to June 2005 frequent explosions and plumes were detected at Karymsky (BGVN 30:06). In June 2005, the alert level was briefly lowered from Orange to Yellow because of a decrease in seismic and volcanic activity, but it was raised to Orange again on 23 June because of ash and gas plumes which rose to 3 km above the crater.

Karymsky remained at Concern Color Code Orange and seismicity remained above background levels throughout August-December 2005.

Throughout July 2005 ash-and-gas plumes frequently may have risen to 1-3 km above the crater. During 8-15 July, 450-600 shallow earthquakes occurred daily. On 11 July, an ash-and-gas plume extended about 11 km SE. During 15-22 July, 350-700 shallow earthquakes occurred daily. On 22 July, a weak thermal anomaly and a short E-drifting ash-and-gas plume were visible on satellite imagery.

Small ash and gas plumes continued to be emitted in September. A thermal anomaly was visible at the volcano on satellite imagery on 15 September.

Visual observations on 17 October revealed that the lava dome in the volcano's crater had been partially destroyed. Based on seismic data, three ash-and-gas plumes may have risen to 2.5-4 km altitude during 14-16 October. Five ash-and-gas plumes may have reached heights of 2.5-3.5 km altitude on several days during the last week of October 2005. A thermal anomaly at the volcano was visible on satellite imagery.

The lava dome inside the volcano's crater continued to grow during November 2005. Based on seismic data, three gas plumes containing some ash possibly rose 3-3.8 km altitude during 29-31 October and 1 November. Ash plumes were visible on satellite imagery extending NE on 31 October and 2 November. During 4-11 November five gas-and-steam plumes with some ash may have reached heights of 3-3.5 km altitude.

No seismic data were available after 10 November. A thermal anomaly was visible at the volcano on 15 and 17 November. According to seismic data, many weak shallow earthquakes and possible gas-steam plumes with some amount of ash up to 2.5 km altitude were registered on 20-23 November. A thermal anomaly was noted over the volcano during the last week of November and the first week of December. According to satellite data from Russia and USA, ash clouds moving to the SE from the volcano were noted on 6-7 December.

After 3 December the availability of seismic data became very erratic. A thermal anomaly was registered on 9-11 December and 14-15 December. According to satellite data, ash plumes and clouds were noted on 9 and on 10 December, moving SW and SE, and SE and E, respectively.

During the third week of December, many weak shallow earthquakes and possibly ten ash plumes up to 3.6 km altitude were registered. According to Kamchatka Volcanic Eruptions Response Team (KVERT) volcanologists who work near Karymsky, ash explosions rose up to 2.5-3 km altitude on 17-21 December 2005, and extended WSW and ENE. A thermal anomaly was registered over the volcano on 15-21 December. Seismicity indicated that ash explosions from the summit crater continued.

Many weak shallow earthquakes were registered during the last week of December. Ash plumes rose up to 2.5-4 km altitude on 24 December and 26-27 December and extended mainly E and SE from the volcano, and occasionally SW. According to KVERT volcanologists, a new cone approximately 60-80 m in diameter was formed at the summit of Karymsky volcano. A small lava dome 20-30 m in diameter was seen in the cone's crater. According to satellite data from the USA and Russia, a thermal anomaly was registered over the volcano all week.

During April 2006, emerging ash plumes remained visible for up to 145 km

Karymsky was last reported on in BGVN 30:11. After frequent explosions from December 2004 to June 2005 (BGVN 30:06) a brief decrease in seismic and volcanic activity took place but this ended in late June when ash and gas plumes rose to 3 km above the crater. Seismicity remained above background levels throughout August-December 2005. During this period, ash and gas plumes and thermal anomalies were observed at the volcano.

Seismic activity indicated that ash explosions from the summit crater of Karymsky continued during 14-20 January 2006. Ash plumes extending 6-9 km S from the volcano were observed on 12 January and a thermal anomaly over the dome was observed during 13-15 January. According to seismic data, two possible ash plumes rose to 3.0-3.4 km altitude on 14-15 January.

According to reports from pilots of local airlines, ash emissions from Karymsky rose to 4-5 km altitude during 30-31 January. The ash plumes extended 13-29 km to the SW and SE, respectively. A thermal anomaly was visible at the lava dome during 27 January to 3 February, except when the volcano was obscured by clouds on 28 January. KVERT warned that activity from the volcano could affect nearby low-flying aircraft.

Strombolian activity continued through April 2006. During 10 February to 10 March, a large thermal anomaly was visible at the crater and numerous ash plumes were visible on satellite imagery extending as far as 140 km. On 9 March, a pilot reported an ash plume at a height of ~ 3 km altitude.

During 17-24 March, several ash plumes were visible on satellite imagery at a height of ~ 4 km altitude and extending SE and E. A thermal anomaly was seen at the volcano during periods of visibility. About 40-450 small earthquakes occurred daily.

During 7-14 April satellite imagery showed ash plumes extending ~ 40-145 km E and SE of the volcano, and a large thermal anomaly at the crater. Karymsky remained at Concern Color Code Orange from January to April 2006.

During April, May and June 2006, intermittent eruptive activity at Karymsky continued. Pilots had previously reported ash emissions from Karymsky rising to 3-5 km altitude during January to April 2006, during which time Karymsky remained at Concern Color Code Orange (BGVN 31:04). The same color code stayed in effect through August 2006.

Based on interpretations of April-June 2006 seismic data, ash plumes rose to altitudes of between 3 and 8 km. Satellite imagery showed a large thermal anomaly at the volcano's crater from January to August 2006, and numerous ash plumes and deposits extended 10-200 km SE and E of the volcano.

Figure 12. Karymsky had been erupting several times a day for about a week prior to emitting this ash plume on 19 June 2006. The ASTER instrument on NASA's Terra satellite captured this false-color image. Red indicates vegetation, which is lush around the volcano but very sparse on its slopes. The water of Karymskoye Lake appears in blue. The volcano's barren sides are dark gray, and the volcanic plume and nearby haze appear in white or gray. Image courtesy of NASA; created by Jesse Allen, Earth Observatory, using expedited ASTER data provided the NASA/GSFC/MITI/ERSDAC/JAROS and U.S./Japan ASTER Science Team.

According to the Tokyo VAAC, the Kamchatkan Experimental and Methodical Seismological Department (KEMSD) reported that during July 2006 ash plumes reached altitudes between 3 and 7 km. Approximately 100-350 shallow earthquakes occurred daily during 29 June to 3 July, and increased to 1,000 per day during 4-5 July.

Activity at Karymsky continued during 8-14 July, with 250-1000 shallow earthquakes occurring daily. Based on interpretations of seismic data, ash plumes reached altitudes of 5 km.

During late 2006 and into January 2007, ash explosions occurred from the summit crater at Karymsky, continuation of activity observed since the beginning of January 2006 (BGVN 31:04 and 31:07). This report covers activity during August 2006 to early January 2007.

The Kamchatka Volcanic Eruptions Response Team (KVERT) maintained the level of Concern Color Code at orange during the period of reporting, except for the temporary change to yellow during 8-15 September. Throughout this period the dome was a consistent source of thermal anomalies.

Ash plumes reached to ~ 3.0-3.7 km altitude throughout August 2006. Seismicity rose, with a maximum of 500 local shallow earthquakes per day the week of 18 August, and then lowered to 30-70 earthquakes per day the last week of August. Spasmodic tremor registered on 1-12 and 17 August. On 6 August an ash plume extending ~ 10-73 km E and SE was depicted on satellite data. Volcanic plume information sometimes stems from the Airport Meteorological Center (AMC) in Yelizovo (a town 40 km NE of the S-coast town of Petropavlovsk-Kamchatsky; the latter is the Peninsula's capital, largest city, and features both a major airport and a marine port). The AMC reported that on 16 August, pilots saw a Karymsky ash plume at ~ 6.5 km altitude that extended NE.

During September 2006, local shallow earthquakes occurred ~ 30-250 times per day. A satellite image for 12 September showed an ash plume extending ~ 140 km SE. On 10 September volcanologists observed from visual data an ash explosion of ~ [2.3 km] altitude. Other possible ash explosions were thought to occur toward the end of September 2006, reaching heights of ~ 2.5-4.5 km altitude.

Local seismicity peaked the last week of October with a maximum of 550 weak shallow earthquakes per day, but levels declined through November 2006. Possible ash explosions rising ~ 2.5-5.0 km altitude prevailed the month of October and during 10-11 and 18-19 November. On 25 October staff of the Institute of Volcanology and Seismology (IVS) observed a series of ash bursts up to ~ 2.0 km above the summit with ash plumes that extended ~ 100 km E. On days of sufficient visibility during October and November 2006, ash plumes often extended ~ 29-200 km NE, ~ 20-220 km SE, and ~ 55-137 km E (figure 13). On 28 October observers noted an ash cloud extending to 70 km NE of Karymsky.

Figure 13. Satellite image showing Karymsky and environs, with its faint E-directed plume easily visible over the ocean. Karymsky's vent lies ~25 km W of the point where the plume intersects the coast. The image was taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite on 29 November 2006. Courtesy of NASA Earth Observatory.

There were no seismic data the last week of November to the third week December 2006, but satellite data enabled surveillance. Figure 14 shows a 19 December image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on the Terra satellite.

Figure 14. ASTER image of Karymsky ("K" marks the summit) and surroundings taken on 19 December 2006. N is towards the top. The area indicated as hot near the summit (which is false-colored red on color images) indicates a volcanically induced hotspot, and the tiny white streak over the hotspot may be a steam plume. A broad, dark cast spreads E across the right side of the image (the fringes of which are indicated by "F"). This zone narrows to a point near Karymsky's summit; it results from fresh ash deposits draping the landscape. Although myriad ridges and valleys corrugate much of the landscape, a zone without those features resides several kilometers S of the summit. That is Karymsky lake ("Lake"), which lies in a caldera. From Karymsky's summit to the nearest margin of Karymsky Lake, the distance is ~5 km (see maps and scaled images in previous reports, Eg. BGVN 21:05, 31:07). This NASA image created and interpreted by Jesse Allen, NASA Earth Observatory, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and US/Japan ASTER Science Team.

During the week of 29 December and the first week in January 2007 there were multiple weak local shallow earthquakes. They occurred at a rate of 100-130 per day during the week of 29 December. On 29 December and 1-3 January tremor was also registered.

According to visual information from pilots of international air flights (reported by AMC, Yelizovo), on 2 December an ash plume rose up ~ 6.9 km altitude and extended E. At 0200 on 22 December an ash plume rose up to ~ 7.0 km altitude and extended E. A number of ash plumes extending 9 to 240 km E were observed during December. At the end of December 2006 and into early January 2007, a possible lava flow was observed on a flank of the volcano.

Ongoing explosions that began in 1996 continued through September 2008

Karymsky stratovolcano, one of most active of the Eastern Volcanic Zone of the Kamchatka arc, began an eruptive cycle in January 1996 lasting through at least September 2008. This report covers activity from June 2008 to September 2008 (figure 15).

Figure 15. A photo from December 2007 showing a plume emerging from Karymsky's summit crater with lake-filled Academy Nauk caldera in the background. Photo by A. Ozerov.

During June-September, there were alternating periods of strengthening and weakening activity. Ash plumes were emitted and hot avalanches repeatedly descended the flanks. Seismic events usually had local magnitudes (ML) less than 2.5. Local shallow earthquakes were associated with crater explosions. Satellite data registered thermal anomalies usually on the crater, suggesting the eruption of hot magmatic material such as a lava flow or fragmental avalanches. An increase in the anomaly to 4-7 pixels usually accompanied a lava flow. Code Orange days during the reporting period occurred on the following days (table 4).

Table 4. Thermal anomalies at Karymsky from NOAA-15 satellite images and visual observations for the interval from June to September 2008. Courtesy of Kamchatka Branch of the Geophysical Service of the Russian Academy of Sciences (KB GS RAS).

This report summarizes activity at Karymsky from February 2007 to 23 January 2009, with the exclusion of June-September 2008 (figure 16), when activity was variable (BGVN 33:07). During the reporting interval the Level of Concern Color Code remained at Orange. Overall activity during 2007 was also variable, but increased during July-December 2007 (figure 17).

Figure 16. Recent Karymsky reporting in the Bulletin (shaded areas) and the gaps in coverage discussed in this report.

Figure 17. Activity of Karymsky during 2007: a) the map of epicenters; b) the projection of hypocenters in the elevation along the line AB. Radius of the circle around the volcano is 10 km; c) a quantity of weak local earthquakes ("-50" values indicate no data); d) ash plumes according to visual data, altitude in meters above sea level; e) the size of thermal anomaly in the pixels. (Senyukov and others, 2008).

During February to April 2007, activity was characterized by constant ash explosions and steam-and-gas emissions. Thermal anomalies were detected, and plumes rose to altitudes of 2.5-5.0 km before drifting NW, N, NE, E, and SE (figure 18).

Figure 18. Explosive activity seen at Karymsky in April 2007. Ash covered the volcano, and to less extent the frozen surface of lake Akademia Nauk (the flat area in the foreground) and surroundings. Photo by Alexander Sokorenko.

During May 2007 the volcano quieted; activity was characterized by low steam-and-gas emissions. There was increased seismicity in July-October 2007, with a daily high of 900 events in mid-July. During 21-27 September ash plumes extended over 450 km E, and on 5, 7, and 8 October ash plumes that rose to 30 km altitude drifted E and NE. Activity decreased after November, but steaming was evident (figure 19).

Figure 19. Karymsky viewed from the SW, December 2007. The environment on the upper flanks includes diverse processes that constructed and exposed deposits of black ash inter-layered with snow and ice. For example, precipitation from the active plumes, can variably drop snow, sleet, and rain. Frequent ashfalls occur at Karymsky, in some cases dropping still-warm ash on the snow. Other processes include episodes of freezing and snowfall. Heating from sunlight and seasonal changes may cause local melting. These kinds of processes led to the apron of exposed ash on the S side of the upper cone. Photo by Alexander Sokorenko.

During March-April 2008 explosive activity again increased. On 15-16 March an ash plume drifted 40 km to the SE, and ash deposits were noted 15-20 km to the NE and ESE of the summit. On 3 April ash deposits were noted in areas about 20 km to the E, 70 km to the SW, and 45-50 km to the S. On 8 April an ash plume drifted 70-80 km ESE.

On 11 October 2008 an ash plume rose to an altitude of 3.4 km, and on 13 October a 5-km-wide ash plume drifted 32 km NNE. On 2 November an ash plume rose to an altitude of 4 km. On 10 November an ash plume drifted 38 km E, and 28 km ENE. On 15 November an ash plume extended 28 km to the E. On 8 December ash plumes rose to altitudes of 2 km and ash deposits on the E flank were more than 5 km long. On 16 December an ash plume extended 240 km to the SE and ESE. During 21-23 December ash plumes extended about 80 km to the E. Ash deposits were noted on 21 December; the deposits extended 26 km SE and 9 km NE.

As late as 8 and 12 January 2009, gas-and-steam plumes extended about 25 km to the SE and NE. The Tokyo VAAC reported that on 16 January an ash plume rose to an altitude of 3.7 km and drifted SE. Analysis of satellite imagery revealed a thermal anomaly in the crater during 18-19 and 21 January 2009.

This report covers 23 January to 9 September 2009, an interval with both thermal anomalies and ash plumes. A new explosion crater formed on the upper S flank on 14 August 2009. Many thermal anomalies were detected during 21 February to 1 March 2009 (figure 20).

Figure 20. A plot of thermal anomalies registered during 1 February to 4 June 2009. Data provided in lower table. Courtesy of the Kamchatka Branch of the Geophysical Service of the Russian Academy of Sciences.

During March 2009, Karymsky plumes were abundant (table 5). They were extending up to 200 km long on the 12th and 16th-17th. During 25 April and 19 May activity decreased although gas-and-steam emissions continued (figure 21).

Table 5. Summary of plumes observed at Karymsky during 21 February to 4 June 2009. Data compiled from listed sources.

Figure 21. Karymsky as seen on 18 April 2009. View was from the SE. Photo by A. Manevich.

Volcanologists reported from a camp on Karymsky lake that at 1600 on 14 August 2009 they noticed a series of small ash emissions. They saw plumes rising to ~ 2.5 km altitude. As a result of the eruption, a crater formed on the volcano's upper S slope. The new explosion crater was round and deep, with a diameter of 70 m. At the time of the call the crater was still steaming to a height of 200 m above the crater (figure 22).

Figure 22. Explosion crater on the S slope of Karymsky as seen on 18 August 2009 (four days after it formed). Photo by S. Chirkov.

This report on Karymsky covers September 2009 to September 2010, an interval with consistent thermal anomalies, seismic activity, and ash plumes. This report was written primarily by Jason Kaiser as part of a graduate student writing assignment in a volcanology class at Oregon State University under the guidance of professor Shan de Silva.

Activity during September 2009-September 2010 was similar to reported activity during January to September 2009 (BGVN 34:08), characterized by nearly consistent thermal anomalies (when cloud cover allowed satellite observations) and above-background seismic activity (figure 23). Ash plume altitudes averaged between 3.5 and 4 km, occurring at least once a week for large portions of this time period. These plumes typically drifted between 100 and 200 km E over the N Pacific Ocean. Ash plume altitudes reported by Kamchatka Volcanic Eruptions Response Team (KVERT) were mostly based on seismic data interpretation, rather than direct observation. Information on thermal anomalies, seismic activity, and ash plume dispersal was reported by KVERT and Tokyo Volcanic Ash Advisory Center (VAAC); first-hand observations by scientists in the area were rare. Plume altitudes and maximum dispersals during the reporting period are shown in figure 24.

Figure 23. Plots of thermal anomalies (number of pixels per day, top) and seismic events (number per day, bottom) during 9 September 2009-30 September 2010. Courtesy of the Kamchatka Branch of the Geophysical Service of the Russian Academy of Sciences (KB GS RAS).

Figure 24. a) Altitudes of ash plumes from Karymsky during September 2009-September 2010, reported by KVERT and Tokyo VAAC. b) Dispersal directions and distances for plumes in (a) with reported dispersals, plotted in corresponding colors. Yelizovo airport is also shown to the SW of Karymsky. Plot and map view created by Jason Kaiser.

After being lowered to Green in August 2009, the Aviation Color Code was again raised to Yellow on 22 September 2009, then to Orange on 23 September, both times because of increased seismicity and possible ash explosions. Scientists flying near Karymsky in a helicopter on 22 September observed ash plumes that rose to altitudes of 1.7 km and drifted E.

The Aviation Color Code remained at Orange for the rest of 2009. Thermal anomalies and above-background seismicity were common, occurring consistently each week during October-November 2009. Few direct observations were made, but scientists did note fumarolic activity on 1 October and a small ash plume reaching 3.5 km altitude and drifting SSE on 7 October. On 12 October, volcanologists doing fieldwork in the area observed and photographed an ash plume that later rose to an altitude of 3.5 km (figure 25).

Figure 25. KVERT photo of an ash plume emitted by Karymsky on 12 October 2009. The plume later reached an altitude of 3.5 km. Courtesy of A. Manevich (KVERT).

KVERT reported that ash deposits observed in satellite imagery extended 45 km SE on 6 December. No seismic or thermal data were available for 8 December 2009, yet a new lava flow on the S flank was observed on that day. Based on information from Yelizovo Airport, the Tokyo VAAC reported that on 25 December an ash plume rose to an altitude of 6.7 km. That same day, KVERT noted three linear ash deposits in satellite imagery that extended nearly 10 km SE from the vent. Smaller gas-and-steam bursts were observed by scientists in the area three days later.

Thermal anomalies were observed in satellite imagery nearly every day during January-March 2010. Above background seismicity was also common during this period. Ash explosions were assumed to be consistent with the seismic activity during this time frame, and were weak during February. The Aviation Color Code remained at Orange for much of this period, but was lowered to Yellow at the end of February.

KVERT reported that seismicity increased on 25 March 2010. On 27 March an intense thermal anomaly over the volcano was apparent in satellite imagery and ash plumes were observed in the area of the volcano during 28-29 March, drifting 250 km SSE (the longest reaching ash plume during this reporting interval, table 6). The Aviation Color Code was again raised to Orange on 29 March.

Thermal anomalies and above-background seismicity were noted consistently throughout April 2010. KVERT reported ash plumes drifting 40-130 km SE on 17 and 21 April. Volcanologists working in the area on 20 and 21 April observed ash bearing gas-and-steam plumes that rose to an altitude of 3 km. Strombolian activity was occasionally observed at night (figure 26).

Figure 26. Strombolian activity at Karymsky observed during the night of 18 April 2010. Courtesy of S. Ushakov (KVERT).

During May-August 2010 ash plumes were common, occurring fairly consistently each week, and sometimes confirmed by satellite imagery. Based on information from Yelizovo Airport and KVERT, Tokyo VAAC reported that ash plumes rose to an altitude of 4.3 km a.s.l. and drifted SW and W on 22 and 25 May. During 25 June-2 July seismicity at Karymsky was above background levels and suggested that possible ash plumes rose to altitudes up to 7 km a.s.l. Strong thermal anomalies were detected on 27 June. Ash plume altitudes over this period are plotted in figure 24a.

The Aviation Color Code remained at Orange through September 2010 due to consistent thermal and seismic anomalies. Seismic data suggested some intervals where ash plumes rose from the volcano almost daily. September ash plumes were repeatedly calculated or observed in satellite imagery to reach maximum altitudes of 4 km. Dispersal estimates were rare during September 2010 due to limited visibility, but were not reported to be greater than 100 km to the SSE (figure 24b, table 6).

This report summarizes activity at Karymsky from September 2010 to 31 December 2013. This period was characterized by frequent explosions with ash plumes, and persistent thermal anomalies. During this period, explosions catapulted ash to altitudes as high as 6.5 km (and possibly higher). According to Girina and others (2013), Karymsky has been in a state of explosive eruption since 1996.

The Kamchatka Volcanic Eruptions Response Team (KVERT) monitors the volcano by seismic instruments and by satellite. Occasionally, pilots and volcanologists observe the volcano visually; however, the volcano is frequently shrouded by clouds. KVERT does not directly observe ash plumes, but infers their presence and their maximum altitudes based upon seismic data, although sometimes satellite observations are used. Occasionally, plume altitudes and directions are provided by the Tokyo Volcanic Ash Advisory Center (VAAC), based on information from Yelizovo Airport (UHPP). The Aviation Color Code was Orange (the second highest) throughout the reporting period. This report is based on weekly KVERT online reports.

Figures 27 and 28 show Kamchatka and Karymsky in the context of both geography and representative aviation flight paths. Since Karymsky sits directly below a principal flight route and close to many others, tall ash plumes from Karymsky present an acute hazard to aircraft. More than 200 flights per day occurred over the North Pacific region at the end of 2007 (Neal and others, 2007). That translated to over 10,000 passengers and millions of dollars in cargo that flew across the North Pacific every day (Neal and others, 2007).

Figure 27. The Northern Pacific region showing major Holocene volcanoes in red and selected aeronautical flight paths across the Russian Far East and North Pacific. Karymsky lies nearly directly below the major, bidirectional flight path G583. Taken from Neal and others (2009).

Figure 28. A smaller-scale map than the one above, centered on the Kamchataka Peninsula showing major Holocene volcanoes including Karymsky, with a more detailed view of flight routes (arrows show directions of travel). Seismically monitored volcanoes are distinguished from those unmonitored, with about 30 real-time seismometers available in the region as of 2008. Alaid volcano, just S of Kamchatka, is the subject of a separate report in this issue of the Bulletin. Taken from Neal and others (2009).

September 2010-December 2012 activity. During September 2010-December 2010, KVERT weekly reports stated that seismic activity was at or above background levels. During January 2011-December 2012, most reports characterized the seismic activity as moderate. However, KVERT stated that activity was weak and moderate between 23 August-20 September 2012, during the week before 25 October 2012, and during all of December 2012. Activity was weak during the first week of July 2012.

According to KVERT, one or more ash explosions occurred weekly, and ash plumes rose to altitudes of 2-6.5 km, with most weekly values in the altitude range of 2.5-5 km. Explosive activity apparently weakened slightly during April and May 2012, with plume altitudes decreasing to 1.8-2.5 km, and apparently weakened further between mid-July and mid-August 2012, when KVERT did not report any ash plumes.

Figure 29 shows an image captured the MODIS instrument during May 2011. A plume is discernable to the edge of the image, ~140 km ESE. Radiating from the volcano is a pattern of recent ash fall deposits contrasting with broad snow cover.

Figure 29. Satellite image of Karymsky acquired on 7 May 2011. Evidence of frequent eruptions is visible in this natural-color satellite image. Dark gray ash extends away from Karymsky's summit covering sectors of the volcano in radial patterns. A plume of ash extends to the SE, over Kronotskiy Kroniv (Kronotsky Gulf). The image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite. Courtesy of NASA's Earth Observatory (image by Jeff Schmaltz and original descriptive material by Robert Simmon).

During mid-September 2012, ash plume altitudes reached 5.5-6 km, but had decreased to a more normal 3 km in December 2012. On 11 April 2012, instruments aboard the Terra satellite detected ash deposits about 15 km long on the E flank. According to the Tokyo VAAC, an ash plume rose to an altitude of 7.3 km and drifted N on 13 March 2011, and to an altitude of 5.5-11.9 km and drifted SW on 18 April 2011; the Tokyo VAAC reported several other ash plumes during the reporting period, but the two mentioned here represent the maximum plumes heights recorded during the reporting period.

KVERT reported Stombolian activity during October 2010. A thermal anomaly was reported every week during this period, although clouds often obscured satellite data.

On 20 November 2010, volcanologists aboard a helicopter observed moderate gas-and-steam activity. Slopes near the summit were covered with ash. According to KVERT, volcanologists also visually observed weak gas-and-steam activity on 18 December 2012.

2013 activity. During January through March 2013, seismic activity fluctuated from weak to moderate. During April through mid-August, seismic activity was not recorded for technical reasons. From mid-August through the end of 2013, activity was moderate. When satellite data was included in 2013 KVERT weekly reports (6, 14 March; 11, 18 July; 5, 12, 19 September; 3 October), the volcano was either quiet or obscured by clouds.

KVERT reports from 10 October 2013 through at least 2 January 2014 stated that Strombolian and weak Vulcanian activity probably had occurred, because satellite data sometimes showed a bright thermal anomaly over the volcano along with ash plumes (figure 30). The reports did not mention this activity during earlier portions of the reporting period (September 2010-December 2013), except for mid-October 2010; however, because thermal anomalies persisted throughout the reporting period and ash plumes were common, we suspect that Strombolian and weak Vulcanian activity probably occurred often during this time.

During 2013, ash plumes seldom exceeded an altitude of 3.5 km. However, powerful ash explosions up to an altitude of 6 km were observed on 5 August by a helicopter crew and volcanologists on the flank of nearby Tolbachik volcano.

Lopez and others (2012) used "coincident measurements of infrasound, SO2, ash, and thermal radiation collected over a ten day period at Karymsky Volcano in August 2011 to characterize the observed activity and elucidate vent processes. The ultimate goal of this project is to enable different types of volcanic activity to be identified using only infrasound data, which would significantly improve our ability to continuously monitor remote volcanoes. Four types of activity were observed. Type 1 activity is characterized by discrete ash emissions occurring every 1- 5 minutes that either jet or roil out of the vent, by plumes from 500-1500 m (above vent) altitudes, and by impulsive infrasonic onsets. Type 2 activity is characterized by periodic pulses of gas emission, little or no ash, low altitude (100 - 200 m) plumes, and strong audible jetting or roaring. Type 3 activity is characterized by sustained emissions of ash and gas, with multiple pulses lasting from ~1-3 minutes, and by plumes from 300-1500 m. Type 4 activity is characterized by periods of relatively long duration (~30 minutes to >1 hour) quiescence, no visible plume and weak SO2 emissions at or near the detection limit, followed by an explosive, magmatic eruption, producing ash-rich plumes to >2,000 m, and centimeter to meter (or greater) sized pyroclastic bombs that roll down the flanks of the edifice. Eruption onset is accompanied by high-amplitude infrasound and occasionally visible shock-waves, indicating high vent overpressure."

The above meeting abstract ultimately led to the paper Lopez and others (2013). In the abstract for that work, the authors characterized the four types of activity as: (1) ash explosions, (2) pulsatory degassing, (3) gas jetting, and (4) explosive eruption.

Ongoing eruptions, often on a near daily basis, prevailed during January-March 2014, with thermal anomalies on satellite data, ash plumes hundreds of meters over the ~1.5 km summit's elevation. The plumes were visible in imagery for over 100 km downwind (often in the sector NE-E-SE).

During 2014 Karymsky volcano on the Kamchatka Peninsula continued its eruptive activity that had been ongoing since November 2001. Strombolian and Vulcanian activity with ash plumes as high as 4.5 km, bright thermal anomalies, and moderate seismic activity were reported by the Kamchatka Volcanic Eruption Response Team (KVERT), the Tokyo Volcanic Ash Advisory Center (VAAC) and the MODVOLC thermal alert system. The volcano was active early in the year, especially during January through April, quieted down from May through August, and then became more active again in September.

Ash plumes were reported on six different dates in January (1, 8, 18, 19, 20 and 22) (table 7), and thermal anomalies were reported on seven dates (6, 9, 18, 22, 24, 26, and 29). KVERT reported continuing moderate explosive eruptions and bright thermal anomalies all month. Moderate seismic activity was only recorded during the last week due to technical problems.

Table 7. Ash plumes reported for Karymsky during January-April 2014.

Date

Altitude (km)

Distance (km)

Direction

Report Source

01 Jan 2014

1.5-2

120

SE

KVERT VONA

08 Jan 2014

--

10

SSE

KVERT Weekly

18 Jan 2014

2.5-3

40

SSE

KVERT VONA

19 Jan 2014

3

--

SSE

Tokyo VAAC

20 Jan 2014

--

110

E

KVERT Weekly

22 Jan 2014

2.0-2.5

60

E

KVERT VONA

22 Jan 2014

1.5-2

110

E

KVERT VONA

01 Feb 2014

--

80

E

KVERT VONA

28 Feb 2014

1.5-2

55

NE

KVERT VONA

12 Mar 2014

1.5-2

40

SW

KVERT VONA

12 Mar 2014

1.5-2

75

SW

KVERT VONA

12 Mar 2014

1.5-2

70

SE

KVERT VONA

13 Mar 2014

1.5-2

230

SE

KVERT VONA

16 Mar 2014

2.0-2.5

40

ESE

KVERT VONA

16 Mar 2014

1.5-2

107

SE

KVERT VONA

17 Mar 2014

1.5-2

100

SE

KVERT VONA

17 Mar 2014

1.0-1.5

90

SE

KVERT VONA

18 Mar 2014

2.0-3.0

120

NE

KVERT VONA

20 Mar 2014

1.5-2

70

SE

KVERT VONA

21 Mar 2014

2

--

SE

Tokyo VAAC

24 Mar 2014

2.5-3

180

SE

KVERT VONA

27 Mar 2014

2.0-2.5

100

ESE

KVERT VONA

28 Mar 2014

2

--

E

Tokyo VAAC

31 Mar 2014

1.5-2.0

20

SE

KVERT VONA

01 Apr 2014

1

50

SW

KVERT VONA

04 Apr 2014

--

100

E

KVERT Weekly

06 Apr 2014

2-3

--

--

Tokyo VAAC

12 Apr 2014

2-3

--

--

Tokyo VAAC

19 Apr 2014

2-3

--

--

Tokyo VAAC

In February, KVERT reported moderate seismicity indicating ongoing moderate explosive eruptive activity all month. Only two ash explosions were recorded, a small one on 1-2 February drifting 80 km E and a larger plume on 28 February rising to 1.5-2 km altitude and drifting 55 km NE. Ten MODIS thermal anomalies were recorded on six different dates (2, 12, 14, 15, 16, and 19). KVERT also indicated bright thermal anomalies visible daily during the last two weeks of the month.

Significantly more ash plume activity was recorded in March 2014, with KVERT issuing VONA (Volcano Observatory Notification to Aviation) reports on nine different dates (table 7). Late on 12 March 2014 a plume was observed with dimensions of 60 x 15 km located 70 km S of the volcano along Cape Shipunsky. MODIS thermal anomalies were recorded on 11, 16, 18, and 27 March and KVERT reported bright thermal anomalies all month. KVERT weekly reports indicated moderate seismic activity indicating continued explosive eruption activity all month.

Moderate seismic activity indicating continued explosive eruption was observed by KVERT during all of April, even though they only issued one VONA report on 1 April indicating a 1 km ash plume drifting 50 km SW. Tokyo VAAC reported additional possible plumes on 6, 12, and 19 April, drifting in different directions to heights of 2-3 km. The KVERT weekly reports indicated ash plumes were drifting about 100 km SW on 1 and 2 April (figure 31) and 100 km E on 4 April. No thermal anomalies were reported by MODIS in April, although KVERT reported a bright thermal anomaly the first week, and thermal anomalies on several other days that were not clouded over each subsequent week.

Figure 31. A modest explosion at Karymsky on 2 April 2014. View is approximately towards the NNW. Photo taken by A. Sokorenko (Institute of Volcanology and Seismology, Far Eastern Branch, Russian Academy of Science).

No ash plume reports were recorded from May through August, although KVERT noted moderate seismic activity in May and June. Thermal anomalies were recorded twice by MODIS, on 1 and 5 May, and were indicated by KVERT often during the first two weeks of the month and again on 25 and 27 May. MODVOLC did not record any more thermal anomalies for Karymsky in 2014. KVERT reported thermal anomalies on 11, 12, 13, and 16 June. The seismicity reported by KVERT decreased to "weak" in the second week of July (figure 32), and did not return to moderate levels until the week ending on 19 September. After mid-June, no thermal anomalies were reported until 27 August. As a result of reduced activity at the volcano in June and July, KVERT lowered the Aviation Color Code (ACC) from Orange to Yellow on 24 July.

Figure 32. Aerial view of the Karymsky crater during quiet conditions on 22 July 2014. Photo by S. Samoilenko (Institute of Volcanology and Seismology FEB RAS, KVERT); courtesy of KVERT.

A 4-km-high ash plume on 3 September extended 9 km WSW and prompted the first VONA Report from KVERT since April. Tokyo VAAC reported another ash plume on 10 September that rose to 2 km and drifted SW and then S. It was reported in the KVERT Weekly Report as extending 100 km to the SE (figure 33). Another VONA report on 15 September noted an ash plume at 3 km altitude 40 km SE of the volcano that was reported by AMC Elizovo helicopter pilots. KVERT reported weak thermal anomalies on 12 and 13 September and an ash plume drifting about 191 km E on September 28.

Figure 33. Aerial photo of Karymsky looking towards the north with a plume rising from the crater on 10 September 2014. Photo by Igor Sesterov, Institute of Volcanology and Seismology FEB RAS, KVERT; courtesy of KVERT.

Weak and moderate seismic activity during November and a weak thermal anomaly on 29-30 November reported by KVERT indicate that the volcano did not have any major explosions that month, but another ash plume was observed by AMC Elizovo helicopter pilots on 10 December according to KVERT; the plume rose to 4.5 km altitude and drifted 30 km W.

Karymsky volcano on Russia's Kamchatka Peninsula has a lengthy eruptive history based on both radiocarbon data (back to about 6600 BCE) and historical observations (back to 1771). Much of the volcanic cone is surrounded by lava flows less than 200 years old. The most recent activity, consisting of frequent ash explosions and a few lava flows deposited on the flanks, has been ongoing for several decades. The most recent previous report described numerous ash explosions, persistent thermal anomalies, and moderate seismic activity through 2014 (BGVN 40:09). This report covers similar activity from January 2015 through May 2017. Information was compiled from the Kamchatka Volcanic Eruptions Response Team (KVERT), the Tokyo Volcanic Ash Advisory Center (VAAC), and several sources of satellite data.

Ash-bearing explosions and thermal anomalies characterized activity throughout 2015, beginning with an explosion on 19 January. Ash plumes were common through early March 2016, after which only steam-and-gas emissions and occasional thermal anomalies were noted, although fresh ash deposits were observed near the volcano in the second half of March. A brief episode of explosive activity during 5-8 October 2016 produced low-level ash plumes that drifted for hundreds of kilometers. No additional activity was reported through May 2017.

Activity during 2015. An explosive event at Karymsky on 19 January 2015 signaled a return to activity after a few months of quiet. The ash plume from the explosion extended 50 km SE, and the NASA Earth Observatory captured a satellite image showing trace ash deposits from the event trending SE across the snow-covered landscape (figure 34). Ashfall deposits were seen on 1 March (10-15 km E and SE) and 7 March.

Throughout the year, KVERT reported multiple thermal anomalies and ash plumes each month (table 8). The Tokyo VAAC issued 192 aviation alerts during the year, and the MODVOLC system reported eight thermal alerts in January, one in July, and two in August. Ash plume altitudes ranged from 2.1 to 7 km. Continuous ash emissions were noted during 16 and 29-30 July. The ash plume observed in satellite data on 17 July was 8 km long and 5 km wide. Volcanologists observed multiple explosions during 21-22 July, and helicopter pilots in the area reported explosions on 28 July that then lasted for several days (figure 35). Large plumes were also noted during December; on 22 December one was 8 km long and 6 km wide, and on 25 December one was 56 km long and 6 km wide. The highest altitude plumes were reported at 7 km drifting N on 16 and 20 November 2015 by the Tokyo VAAC. Ash plumes drifted in various directions, and were observed as far as 250 km before dissipating.

Table 8. Summary by month of ash plumes and thermal anomalies reported for Karymsky during 2015. Details include dates of thermal anomalies and ash plumes, maximum plume altitude in kilometers, distance in kilometers of ash plume drift, and direction of drift. Multiple thermal anomalies on a given date are shown in parentheses- 23(4)-after the date. 'Date: 7/8' means time zone boundaries presented different reported days for Kamchatka time (KST) and Universal Time (UTC). Sources are KVERT and Tokyo VAAC for ash plume data; KVERT and MODVOLC for thermal data.

Month

Thermal Anomalies (KVERT)

Thermal Anomalies (MODVOLC)

Ash Plumes

Plume Altitude (km)

Plume Distance (km)

Plume Directions

Jan 2015

11, 18-31

19, 22(2), 23(4), 26

19-23, 27, 31

2.5-5

65-160

ESE, E, N

Feb 2015

6, 21, 24

--

23, 27

2.7

254, 215

ENE

Mar 2015

7, 24-26, 29

--

22, 24-26, 27, 29-30

2.1

154, 150

E, NE, SW

Apr 2015

9, 16-17, 23

--

3, 23, 27

2.7-3.0

85, 35, 140

SE, SE, NE

May 2015

4-6, 15-16, 30

--

16/17, 23

--

27, 45

W, SE

Jun 2015

6, 8-10

--

8-10

4.3

50

SE, E

Jul 2015

6, 13-14, 16, 17, 25, 27-30

13

1, 9, 13, 17, 21-22, 25, 27-30

2-5.1

50-115

SW, S, E, NW, SE

Aug 2015

2, 6, 15, 18-21, 24-25

19, 24

2, 6, 8, 9, 12, 15, 16, 18, 21, 24, 25

4.3-5.8

25-54

N, W, SW, SE

Sep 2015

2, 10, 14-18, 24

--

8, 10, 20

4.3-4.6

10

SE, NE

Oct 2015

4, 8, 11, 20, 22-24, 28

--

3-5, 8, 17-20, 22

2.1-4.6

50, 100

SE, E

Nov 2015

20, 27

--

1/2, 4, 7/8, 10-12, 15-18, 20-21, 30

2.5-7.0

40-160

NE, SE, E, ESE

Dec 2015

3, 6-7, 14, 23-25, 27-28, 31

--

11, 19, 22, 25, 28

3.7-5.5

145

E, NE, NW, W, ENE

Figure 35. Ash plume from an explosion at Karymsky on 30 July 2015. Photo by E. Kalacheva, IVS FEB RAS, courtesy of KVERT.

Activity during January 2016-April 2017. Activity was variable at Karymsky during 2016 (table 9). The Tokyo VAAC issued 132 aviation notices. Ash plumes and thermal anomalies were most frequent during January and February, with over twenty instances of each during February. The plume heights during February exceeded 6 km altitude four times, with the highest plume of the year on 20 February at 7.6 km altitude. Near-continuous ash emissions during the last week of February resulted in satellite observations of ash deposits around the volcano at the end of the month and during the first few days of March (figure 36). Activity decreased significantly during March, although KVERT noted fresh ash deposits again during 18-25 March. Except for thermal anomalies noted on 1 and 6 April, only steam-and-gas emissions were reported; KVERT lowered the Aviation Alert Level from Orange to Yellow (on a four-color scale) at the end of the month. From May to July, KVERT reported a thermal anomaly once each month. Steam-and-gas emissions were the only activity reported in August, and on 2 September, they lowered the Alert Level from Yellow to Green.

Table 9. Summary by month of ash plumes and thermal anomalies reported for Karymsky during 2016. Details include dates of thermal anomalies and ash plumes, maximum plume altitude in kilometers, distance in kilometers of ash plume drift, and direction of drift. Sources are KVERT and Tokyo VAAC for ash plume data; KVERT and MODVOLC for thermal data.

Month

Thermal Anomalies (KVERT)

Thermal Anomalies (MODVOLC)

Ash Plumes

Plume Altitude (km)

Plume Distance (km)

Plume Directions

Jan 2016

1, 3-4, 6-7, 11-15, 18-19, 21, 23, 26, 31

--

3, 5-7, 9, 10, 12-15, 17, 21, 24, 26-28, 31

3.9-7.6

160-270

E, NW, SE

Feb 2016

1-19, 22, 26-29

5

1-21, 26

3.4-7.6

125-270

E, SE, W

Mar 2016

1-4

--

1

5.2

--

NE

Apr 2016

1, 6

--

--

--

--

--

May 2016

26

--

--

--

--

--

Jun 2016

25

--

--

--

--

--

Jul 2016

4

--

--

--

--

--

Aug 2016

--

--

--

--

--

--

Sep 2016

--

--

--

--

--

--

Oct 2016

7, 12, 17

--

5-8

2.4

390

E, SE

Nov 2016

3

--

--

--

--

--

Dec 2016

--

--

--

--

--

--

Figure 36. Steam plume from Karymsky on 21 February 2016, and abundant fresh ashfall around the volcano from recent ash emissions. Photo by E. Nenasheva, courtesy of KVERT.

After six months of quiet, the Tokyo VAAC reported an ash plume on 5 (UTC)/6 (KST) October at 2.4 km altitude extending SE. Aviation alerts were issued through 8 October 2016. Although residing at a fairly low altitude (2.4 km), the plume observed in satellite imagery during 7-8 October was visible in satellite imagery drifting 390 km E and SE before dissipating. KVERT briefly raised the Alert Level to Yellow and then to Orange on 7 and 8 October, and then back to Yellow on 19 October. Three weak thermal anomalies appeared in October and one in November; KVERT lowered the Alert Level to Green on 25 November. Karymsky remained at Alert Level Green through May 2017 with no further reports issued from KVERT or the Tokyo VAAC.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Basic Data

Volcano Types

Rock Types

MajorAndesite / Basaltic Andesite
Dacite

Tectonic Setting

Subduction zoneContinental crust (> 25 km)

Population

Within 5 kmWithin 10 kmWithin 30 kmWithin 100 km

0
0
291
10,848

Geological Summary

Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed during the early Holocene. The caldera cuts the south side of the Pleistocene Dvor volcano and is located outside the north margin of the large mid-Pleistocene Polovinka caldera, which contains the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding Karymsky eruptions originated beneath Akademia Nauk caldera, located immediately south. The caldera enclosing Karymsky formed about 7600-7700 radiocarbon years ago; construction of the stratovolcano began about 2000 years later. The latest eruptive period began about 500 years ago, following a 2300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been vulcanian or vulcanian-strombolian with moderate explosive activity and occasional lava flows from the summit crater.

References

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography.

Emission History

There is no Emissions History data available for Karymsky.

Photo Gallery

This false-color satellite image shows many calderas of the Zhupanovsky (Karymsky) volcano-tectonic depression. Lake-filled Akademia Nauk caldera (bottom) truncates the older Odnoboky caldera, whose rim is seen south of the lake. Both these calderas were constructed within the larger mid-Pleistocene Polovinka caldera, whose rim appears at the lower right. The dark area in the center is the frequently active Karymsky volcano, whose lavas fill an early Holocene caldera. The light-colored area immediately to its north is Dvor caldera.

Photo courtesy Dan Miller (U.S. Geological Survey).

The scenic lake-filled Akademia Nauk caldera, seen here from the north with Kaymsky volcano in the foreground, is one of three volcanoes constructed within a large mid-Pleistocene caldera. Two nested calderas, 5 x 4 km Odnoboky and 3 x 5 km Akademia Nauk (also known as Karymsky Lake), were formed during the late-Pleistocene. The first historical eruption from Akademia Nauk did not take place until January 2, 1996, when a brief, day-long explosive eruption occurred from vents beneath the NNW part of the caldera lake.

Photo by Dan Miller (U.S. Geological Survey).

Karymsky volcano contained a 250-m-wide summit crater following the 1970-82 eruption. Karymsky Lake fills the 3 x 5 km wide Akademia Nauk caldera to the south in this early 1990's aerial photo. Both Karymsky and Akademia Nauk volcanoes erupted simultaneously on January 2, 1996. The brief one-day eruption was the first historical eruption of Akademia Nauk, but long-term explosive activity continued at Karymsky, one of Kamchatka's most active volcanoes.

Photo by Dan Miller (U.S. Geological Survey).

A small, dark ash column rises above the summit crater of snow-covered Karymsky volcano in this photo taken during the 1970's. More-or-less continuous mild-to-moderate explosive eruptions took place during 1970-82 from Karymsky, one of Kamchatka's most active volcanoes. Lava flows were emitted from the summit crater in 1970, 1971, 1976, and 1979-82.

Photo by Yuri Doubik (Institute of Volcanology, Petropavlovsk).

This eruption plume rising above the summit of Karymsky volcano during the early 1970's was typical of more-or-less constant explosive activity that occurred from the volcano during its 1970-1982 eruption. The symmetrical Karymsky volcano is one of the most active in Kamchatka. It was constructed within a 5-km-wide caldera that formed about 6000 years ago. The northern Karymsky caldera wall cuts across the center of the photo and truncates the caldera of Dvor volcano, which forms the ridge in the background.

Photo by Yuri Doubik, 1972 (Institute of Volcanology, Petropavlovsk).

Symmetrical Karymsky volcano casts a shadow across the floor of the caldera in which it was constructed. The NW caldera wall forms the 300-m-high cliff in the background. Fresh lava flows blanket the caldera floor. The 5-km-wide caldera was formed during one of Kamchatka's largest Holocene eruptions about 7500 radiocarbon years ago. Karymsky was constructed by frequent explosive and effusive eruptions during the past 6000 years. Its latest eruptive period began about 500 years ago.

Photo by Yuri Doubik (Institute of Volcanology, Petropavlovsk).

The lava flow in the center of the photo is an unusual pillow lava that was erupted from Karymsky during a 1960-65 eruption. The pillow lavas, which normally form during submarine eruptions, were erupted subaerially on the NW flank of the cone in March 1963. Intermittent explosive and effusive activity took place from April 1960 to January 1965.

Photo by Oleg Volynets (Institute of Volcanology, Petropavlovsk).

A 200-250 m wide crater occupied the summit of Karymsky volcano following a long-term eruption during 1970-82. This early 1990's photo looks into the crater from the NE. Several other prominent central Kamchatka volcanoes form the snow-capped alignment of volcanoes in the background. Zhupanovsky volcano, at the extreme left, is composed of four overlapping stratovolcanoes constructed along an WNW-ESE line. Sharp-peaked Koryaksky volcano is at the left center, and the broad Dzensursky massif to its right.

Photo by Dan Miller (U.S. Geological Survey).

Symmetrical Karymsky volcano fills much of a 5-km-wide, early Holocene caldera. Its smooth-textured slopes, seen here from the south, are mostly mantled by lava flows and pyroclastic deposits less than 200 years old. Lava flows on this side have overtopped the southern rim of the caldera.

Photo by Dan Miller, 1990 (U.S. Geological Survey).

The eastern margin of Karymsky caldera, which was created about 7500 years ago, forms the steep wall cutting across the center of the photo. Snow mantles the foreground flanks of Karymsky stratovolcano, which was constructed within the 5-km-wide caldera beginning about 5500 years ago. Fresh, dark-colored lava flows from Karymsky cover the caldera moat. The complex, snow-draped stratovolcano to the NE is Maly Semiachik, which has also produced frequent historical eruptions.

Photo by Dan Miller (U.S. Geological Survey).

A crater lake occupies the summit of the youngest and southernmost volcano of Maly Semiachik. All historical eruptions of Maly Semiachik have originated from Troitsky crater. The conical peak in the middle distance is Karymsky volcano, 15 km to the SW. Karymsky was constructed within a Holocene caldera that truncates the southern flank of Dvor volcano (upper right).

Photo by Dan Miller, 1990 (U.S. Geological Survey).

An aerial view from the SW on July 22, 1996 shows an eruption plume rising above the summit crater of Karymsky volcano with Maly Semiachik volcano in the center background. The 1996 eruption began on January 2 simultaneously with an eruption at nearby Akademia Nauk caldera, out of view to the right. The Akademia Nauk eruption lasted only a day, but long-term eruptions continued at Karymsky.

An eruption plume rises above the summit of Karymsky volcano in January 1996. Explosive eruptions began on January 2 from the summit and SW flank of Karymsky volcano. On the same day a powerful explosive eruption took place from Akademia Nauk (Karymsky Lake) caldera, the circular, smooth-textured area to the right of Karymsky's summit. The Akademia Nauk eruption lasted only a day, but long-term activity continued at Karymsky.

Karymsky, one of Kamchatka's most active volcanoes, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed during a major explosive eruption about 7500 years ago. Much of the youthful cone, seen here from a volcanological field camp on the SW flank, is mantled by lava flows less than 200 years old. Frequent historical eruptions have produced long-term explosive activity with occasional lava flows from the summit crater.

Affiliated Sites

The DECADE portal, still in the developmental stage, serves as an example of the proposed interoperability between The Smithsonian Institution's Global Volcanism Program, the MAGA Database, and the EarthChem Geochemical Portal. The Deep Earth Carbon Degassing (DECADE) initiative seeks to use new and established technologies to determine accurate global fluxes of volcanic CO2 to the atmosphere, but installing CO2 monitoring networks on 20 of the world's 150 most actively degassing volcanoes. The group uses related laboratory-based studies (direct gas sampling and analysis, melt inclusions) to provide new data for direct degassing of deep earth carbon to the atmosphere.

WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.

Middle InfraRed Observation of Volcanic Activity (MIROVA) is a near real time volcanic hot-spot detection system based on the analysis of MODIS (Moderate Resolution Imaging Spectroradiometer) data. In particular, MIROVA uses the Middle InfraRed Radiation (MIR), measured over target volcanoes, in order to detect, locate and measure the heat radiation sourced from volcanic activity.

Using infrared satellite Moderate Resolution Imaging Spectroradiometer (MODIS) data, scientists at the Hawai'i Institute of Geophysics and Planetology, University of Hawai'i, developed an automated system called MODVOLC to map thermal hot-spots in near real time. For each MODIS image, the algorithm automatically scans each 1 km pixel within it to check for high-temperature hot-spots. When one is found the date, time, location, and intensity are recorded. MODIS looks at every square km of the Earth every 48 hours, once during the day and once during the night, and the presence of two MODIS sensors in space allows at least four hot-spot observations every two days. Each day updated global maps are compiled to display the locations of all hot spots detected in the previous 24 hours. There is a drop-down list with volcano names which allow users to 'zoom-in' and examine the distribution of hot-spots at a variety of spatial scales.

EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).